Boost Your Team’s Productivity with SharePoint Calendar Overlay

Calendar overlays in SharePoint are a powerful tool that allows you to combine multiple calendars into one unified dashboard, simplifying event and schedule management for teams. By merging personal, team, and corporate calendars, overlays improve scheduling efficiency and ensure everyone stays on the same page.

In this article, you’ll find step-by-step instructions on how to overlay calendars in both SharePoint Online, with its streamlined interface and Exchange Online integration, and SharePoint On-Premises, which requires an on-premises server setup. We’ll also explore additional customization options.

We’ll discuss how the Virto Calendar App for SharePoint Online & Microsoft 365, and the Virto Calendar Web Part for SharePoint On-Premises, can enhance your calendar management, making teamwork more productive and organized.

What Is Calendar Overlay in SharePoint?

In this section, we’ll explain what calendar overlays are, how they work, and the types of calendars that can be overlaid. We’ll also discuss the benefits of using overlays and highlight the differences between SharePoint Online and On-Premises.

Overview of calendar overlays

SharePoint calendar overlay is a feature that allows you to layer multiple calendars into a single, consolidated view. Think of it as stacking transparent calendars on top of each other, where each layer represents a different calendar—whether it’s a SharePoint calendar, an Exchange calendar, or even external calendars. This functionality enables you to view and manage events from various sources without constantly switching between different calendars.

The system supports several calendar types, including:

• SharePoint team calendars
• Exchange Online calendars
• Personal Outlook calendars
• Department-specific calendars
• Project milestone calendars
• Company-wide event calendars

Importance of using calendar overlays

Today, teams often juggle multiple projects, deadlines, and commitments simultaneously. Calendar overlays serve as a crucial tool for effective planning and coordination by:

• Providing a unified view of all team activities
• Preventing scheduling conflicts
• Enabling better resource allocation
• Facilitating cross-team coordination
• Improving overall organizational visibility

For example, a marketing team can overlay their campaign calendar with the sales team’s events calendar and the company’s holiday schedule, ensuring their promotional activities align with key business activities and available resources.

Benefits of calendar overlays

Overlays offer numerous benefits, such as the convenience of accessing multiple calendars in one pane. They provide seamless integration with other calendars, enhancing your ability to manage schedules efficiently and reducing the complexity of juggling various timelines. 

Here’s a detailed look at some of those benefits:

1. Enhanced visibility
   • View multiple calendars simultaneously without switching screens: Instead of juggling between different calendar tabs or applications, users can see all relevant schedules in one unified view. For example, a project manager can simultaneously view their team’s availability, company holidays, and client meeting schedules all on a single screen.
   • Color-code different calendars for easy differentiation: Each calendar can be assigned a distinct color, making it instantly clear which events belong to which calendar. Team meetings might appear in blue, while project deadlines show in red, and company events in green, allowing for quick visual recognition.
   • Quickly identify schedule conflicts and gaps: The overlay feature makes it immediately apparent when multiple events are scheduled for the same time slot or when there are open time slots available for scheduling. This visual clarity helps prevent double-booking and enables better utilization of available time slots.
2. Improved coordination
   • Seamless integration with Exchange calendars: Users can connect their Outlook calendars directly with SharePoint, ensuring that personal and team schedules are always in sync. When a meeting is scheduled in Outlook, it automatically appears in the overlaid SharePoint calendar.
   • Real-time updates across all connected calendars: Any changes made to events in any of the connected calendars are instantly reflected in the overlay view. This ensures all team members are working with the most current scheduling information.
   • Easy sharing of calendar information across teams: Teams can share their calendars with other departments or external stakeholders while maintaining control over which events are visible. This facilitates better cross-functional planning and collaboration.
3. Time management
   • Reduced time spent checking multiple calendars: Instead of spending valuable time switching between different calendar views and mentally combining schedules, users can see everything at once. This can save several hours per week for teams that manage multiple projects or coordinate with various departments.
   • Faster decision-making for scheduling events: With all scheduling information readily available, organizers can quickly identify suitable time slots for meetings or events. This streamlines the scheduling process and reduces back-and-forth communication.
   • Efficient resource allocation: Managers can easily view team availability and workload distribution, enabling better allocation of tasks and resources. This helps prevent team overload and ensures balanced workload distribution.
4. Flexibility
   • Ability to show/hide specific calendars as needed: Users can toggle different calendars on and off depending on their current focus. For instance, when planning a department meeting, you might hide personal calendars and show only team and resource calendars.
   • Customizable views (daily, weekly, monthly): The overlay interface can be adjusted to show different time spans, allowing users to focus on immediate scheduling needs or take a longer-term planning perspective. Each view maintains the color-coding and overlay functionality.
   • Option to aggregate calendars from different departments: Organizations can combine calendars from various departments, locations, or project teams. This is particularly valuable for companies with multiple offices or remote teams, as it provides a comprehensive view of organizational activities.

Differences between SharePoint Online and On-Premises

SharePoint’s calendar overlay functionality varies depending on whether you’re using SharePoint Online or On-Premises. Understanding these differences is important for effectively implementing and managing calendar overlays in your organization.

SharePoint Online:

• Intuitive interface: Features a clean, contemporary design that follows Microsoft’s Fluent UI principles. Users can easily navigate and manage calendars through a user-friendly interface that requires minimal training. The modern experience includes drag-and-drop functionality and intuitive controls for creating and managing events.
• Seamless integration with Exchange Online: Being part of the Microsoft 365 ecosystem means calendar integration happens automatically. Users can connect their Outlook calendars with just a few clicks, and permissions are managed through Azure Active Directory for enhanced security and simplified access control.
• Automatic updates and improvements: Microsoft regularly rolls out new features and security updates automatically. Your organization always has access to the latest calendar functionality without requiring IT intervention. This includes new overlay features, improved performance, and enhanced security measures.
• Simplified setup process: Setting up calendar overlays typically takes just minutes and can be done by users with appropriate permissions. The process involves straightforward steps through the modern interface, with built-in wizards guiding users through the configuration.
• Built-in mobile responsiveness: Calendar overlays automatically adapt to different screen sizes and devices. Users can view and manage overlaid calendars effectively on smartphones and tablets, ensuring productivity on the go.

SharePoint On-Premises:

• Traditional interface: Uses the classic SharePoint interface, which might feel dated but offers extensive customization options. While less intuitive than the modern interface, it provides deeper access to calendar settings and configurations.
• Requires manual configuration for Exchange integration: IT administrators need to manually set up and maintain the connection between SharePoint and Exchange Server. This includes configuring service applications, managing authentication, and ensuring proper server communication.
• More control over server settings: Organizations have complete control over their SharePoint environment, including:
  • Server resource allocation
  • Backup and recovery processes
  • Security protocols
  • Authentication methods
  • Custom web parts and solutions
• Additional setup steps needed: Implementing calendar overlays requires more technical expertise and planning:
  • Server-side configuration
  • Security and permission setup
  • Exchange Web Services configuration
  • SSL certificate management
  • Network connectivity settings
• Custom solutions may be required for advanced features: Organizations often need to develop or purchase additional solutions to achieve functionality that comes standard in SharePoint Online:
  • Advanced calendar visualization
  • Custom calendar templates
  • Specialized reporting features
  • Integration with legacy systems
  • Enhanced mobile access capabilities

Here’s an overview of the above differences in a tabular format for easy reference:

Feature/aspect	SharePoint Online	SharePoint On-Premises
User interface	• Fluent UI design • Drag-and-drop functionality • Intuitive controls • Streamlined user experience	• Classic SharePoint interface • Traditional navigation • More complex menu structure • Feature-rich but less intuitive
Exchange integration	• Automatic integration with Exchange Online • Azure AD-based permissions • One-click calendar connections • Real-time synchronization	• Manual Exchange Server configuration • Custom authentication setup required • Complex permission management • Additional sync configuration needed
Updates & maintenance	• Automatic feature updates • Microsoft-managed security patches • Regular performance improvements • No server maintenance required	• Manual update deployment • Self-managed security updates • Custom patch scheduling • Server maintenance needed
Setup process	• Minutes to configure • Built-in setup wizards • Minimal technical knowledge required • User-level configuration possible	• Hours/days for initial setup • Technical expertise required • IT involvement necessary • Server-level configuration
Mobile access	• Native responsive design • Automatic device adaptation • Consistent cross-platform experience • Built-in mobile apps support	• Manual mobile optimization needed • Custom solutions for responsiveness • Variable device compatibility • Additional mobile setup required
Control & customization	• Limited to Microsoft’s features • Standard add-in options • Preset configuration options • Managed solution scope	• Full server control • Custom development possible • Complete configuration access • Unlimited customization options
Technical requirements	• Minimal IT support needed • Cloud infrastructure • Internet connectivity • Modern browser support	• Dedicated IT team • On-premises servers • Network infrastructure • Database management
Cost structure	• Predictable subscription costs • Included in M365 licensing • No hardware costs • Minimal maintenance costs	• Higher initial investment • Hardware costs • IT staff costs • Ongoing maintenance expenses
Integration capabilities	• Modern API support • Cloud-first integrations • Microsoft 365 ecosystem • Limited legacy system support	• Flexible API options • Custom integrations possible • Legacy system support • Local network integration
Security & compliance	• Microsoft-managed security • Automatic compliance updates • Built-in security features • Global security standards	• Self-managed security • Custom compliance controls • Manual security configuration • Local security policies

👉  Learn more about the differences between SharePoint Online and On-Premises in our dedicated blog article: SharePoint Online vs SharePoint On-Premises: A Comprehensive Comparison [2024]

Can you overlay calendars in SharePoint?

Yes, SharePoint provides robust calendar overlay capabilities that work with various calendar types. The process is straightforward in SharePoint Online and requires some additional configuration in SharePoint On-Premises. You can overlay up to 10 calendars in a single view, each with its own color coding for easy distinction.

Key capabilities include:

• Combining multiple SharePoint calendars
• Integrating Exchange calendars
• Customizing calendar appearances
• Setting different permission levels
• Managing calendar visibility

Whether you need to coordinate team schedules, track project milestones, or manage company-wide events, SharePoint’s calendar overlay feature provides the flexibility and functionality to meet these needs effectively.

For organizations looking to maximize their SharePoint calendar usage, additional tools like the Virto Calendar App (for Online) or Web Part (for On-Premises) can extend these capabilities even further, offering advanced features for more complex scheduling requirements.

How to Create a Calendar Overlay Sharepoint: A Step-by-Step Guide

Now that we understand what calendar overlays are and their benefits, let’s dive into the practical implementation. In this comprehensive guide, we’ll walk through the entire process of creating and managing calendar overlays in SharePoint. We’ll cover everything from initial setup to advanced customization, including setting up basic calendar views, adding and customizing overlays, and configuring Exchange calendar integration. 

How do I add a calendar view in SharePoint? 

Before diving into calendar overlays, let’s ensure you have everything needed for a successful implementation. Let’s walk through each preparation requirement and setup process in detail.

Preparation requirements for Sharepoint calendar overlay 

First, we’ll go through essential prerequisites like permissions, site access, calendar preparation, browser compatibility, and licensing requirements. 

• SharePoint site owner or member permissions 

Before beginning, ensure you have the appropriate access level. Site owners have full control over calendar settings, while members typically have contribute permissions. If you’re unsure about your permission level, contact your SharePoint administrator. Having the right permissions is crucial as it determines what actions you can take during the setup process.

• Access to the desired SharePoint site

You’ll need direct access to the SharePoint site where you plan to implement the calendar overlay. This includes:

• Network connectivity to the SharePoint environment
• Valid login credentials
• Appropriate site collection access
• Access to any subsites where calendars will be created

• Required calendars already created 

Before setting up overlays, ensure all source calendars are properly created and populated. This includes:

• Team calendars
• Department calendars
• Project calendars
• Resource booking calendars Each calendar should have its basic structure and initial events already in place.

• Browser compatibility check 

Ensure you’re using a supported web browser for optimal functionality:

• Microsoft Edge (recommended)
• Google Chrome (latest version)
• Mozilla Firefox (latest version)
• Safari (for Mac users) Note: Internet Explorer is no longer supported for modern SharePoint features.

• Appropriate Microsoft 365 Licenses 

For SharePoint Online users, verify you have one of the following:

• Microsoft 365 Business Basic or higher
• Microsoft 365 Enterprise E1 or higher
• SharePoint Online Plan 1 or 2 Your license level may affect available features and capabilities.

SharePoint Online setup

The modern SharePoint Online interface makes calendar creation straightforward and intuitive. Let’s break down the process:

1. Navigate to your SharePoint site
   • Open your web browser
   • Sign in to your Microsoft 365 account
   • Access your SharePoint site from the app launcher or direct URL
   • Ensure you’re on the correct site where you want to create the calendar
2. Create new calendar
   • Look for the “+New” button in the top navigation
   • Click the dropdown arrow next to “New”
   • Select “Calendar” from the available options
   • Pro tip: If you don’t see the Calendar option, then ensure you have the necessary permissions. If you’re sure you have permissions, try adding your calendar as an App: “+New” > “App”. 

• Some built-in apps are available through the classic experience. If prompted, follow the instructions on screen to switch to classic view and add your calendar app.

3. Name and configure
   • Choose a descriptive name that clearly identifies the calendar’s purpose
   • Consider using a naming convention if you manage multiple calendars
   • Add an optional description to help users understand the calendar’s purpose
   • Click “Create” to generate your new calendar

4. Access calendar settings The modern interface provides several ways to customize your calendar:
   • Click the settings gear icon in the top right or ribbon at the top
   • Select “List settings” from the dropdown menu to navigate to general and specific settings

The modern interface offers several user-friendly features:

• Simplified navigation ribbons: Clearly organized commands and functions
• Clear visual cues: Intuitive icons and buttons that guide users through actions
• Drag-and-drop functionality: Easy event scheduling and calendar management
• Instant preview: See changes in real-time before saving

SharePoint On-Premises setup

The classic SharePoint interface requires a slightly different approach:

1. Site navigation
   • Access your SharePoint On-Premises site
   • Verify you’re logged in with appropriate credentials
   • Navigate to the desired location for your new calendar
2. Calendar creation
   • Click “Site Contents” in the Quick Launch menu or gear icon
   • Select “Add an App” to view available applications
   • Locate and choose “Calendar” from the app options
   • Pro tip: Use the search box if you have many apps installed
3. Calendar configuration Through the classic interface:
   • Access “Calendar Settings” from the ribbon menu
   • Configure basic properties such as name, description, and navigation
   • Set up additional settings specific to your needs:
     • Time zone settings
     • Calendar overlay options
     • Permission levels
     • View settings
     • Versioning settings (if needed)
     • Advanced settings
4. Additional configuration options
   • Set up content types if using different event types
   • Configure custom columns for additional event information
   • Set up views for different user groups
   • Establish workflow processes if required

Remember, while the classic interface might seem less intuitive at first, it often provides more detailed configuration options that can be valuable for complex calendar setups.

By carefully following these preparation steps and setup procedures, you’ll create a solid foundation for your calendar overlay implementation. Take time to verify each step before moving forward, as proper initial setup will save time and prevent issues later in the process.

Step-by-step instructions for adding SharePoint calendar overlays 

Now that we have our base calendar set up, let’s walk through the process of adding and customizing calendar overlays. We’ll cover everything from basic setup to advanced customization options, ensuring you can create a calendar system that perfectly suits your organization’s needs.

Basic overlay setup

1. Access calendar settings

The first step varies depending on your SharePoint version:

For SharePoint Online:

• Click the settings gear icon in the top-right corner or ribbon at the top
• The modern interface provides clear visual cues for each step

For SharePoint On-Premises:

• Look for the “Calendar Settings” option in the ribbon menu
• Navigate through the classic interface
• Note: The location might vary slightly depending on your SharePoint version

2. Add calendar overlay

Once in the settings:

• Locate and select “Calendars Overlay” or “Overlay Settings”—usually found in the calendar settings (or ribbon) menu  

• Click the “New Calendar” button to begin the overlay process

• Choose your calendar type carefully:
  • SharePoint calendars for internal team calendars
  • Exchange calendars for personal or organizational calendars
• Pro tip: Plan your overlay structure before adding multiple calendars

3. Configure overlay settings

Customize your overlay with these essential settings:

Basic configuration:

• Create a clear, descriptive name for easy identification
• Select a distinctive color scheme that makes sense for your organization
  • Consider using consistent colors for similar calendar types
  • Ensure good contrast for visibility
• Input the correct calendar URL for SharePoint calendars
  • Double-check the URL to avoid connection issues
  • Test the connection before saving

Exchange calendar setup:

• Enter Exchange server details if required
• Verify Exchange credentials
• Test the connection to ensure proper synchronization

 Visibility settings:

• Determine who can see the overlay
• Set default view options
• Configure mobile access settings

Customization options

Once your basic calendar overlay is set up, you can take advantage of SharePoint’s extensive customization options to make your calendar system more efficient and user-friendly. Let’s explore the various ways you can tailor your calendar overlays to match your organization’s specific needs.

Display Settings

Let’s walk through how to implement each display setting for your SharePoint calendar overlay, ensuring a well-organized and visually effective system.

Color сoding system:

1. Develop a consistent colour scheme:

• Access calendar overlay settings:
  • Access calendar overlay settings by clicking the gear icon in the top-right corner or selecting “Calendars Overlay” or “Overlay Settings” from the ribbon/menu at the top.

• For each calendar type, assign specific colors:
  • Team Calendars: Blue spectrum (e.g., #0078D4)
  • Project Deadlines: Red spectrum (e.g., #E81123)
  • Training Events: Green spectrum (e.g., #107C10)
  • Company Events: Purple spectrum (e.g., #5C2D91)

2. Priority event colors: Here’s how to set up priority colors in classic SharePoint:
3. First, you need to create a Choice column for priority levels:
   1. Go to “List Settings” (See Pic. 5)
   2. Click “Create Column”

3. Choose “Choice” as the column type
4. Name it “Priority”
5. Add choices: “High Priority”, “Medium Priority”, “Low Priority”
6. Click OK to save

2. Then, add colors to calendar events based on priority by either using:
   1. Conditional formatting
      1. For classic SharePoint, you can use SharePoint Designer to apply conditional formatting by editing the calendar view.
      2. For modern SharePoint, use JSON formatting in the list view to apply color coding based on specific conditions.
   2. Custom scripts
      1. You can use JavaScript or jQuery to apply custom styles to calendar events based on certain criteria.

Note: The exact color customization options might be limited in classic SharePoint compared to modern SharePoint. You might need to use additional customization methods like CSS or SharePoint Designer for more advanced color options.

You can also use the standard category colors that come with SharePoint calendar events, where:

1. Go to calendar event
2. Click “Categorize” in the ribbon
3. Choose from the default color categories provided by SharePoint

3. Document your color system:

• Create a reference guide:
  1. Open SharePoint list
  2. Create new document titled “Calendar Color Guide”
  3. Include:
     • Color swatches with hex codes
     • Purpose of each color
     • Examples of usage
     • Accessibility considerations

Calendar naming convention:

1. Creating clear names:

• Format: [Department]-[Purpose]-[TimeFrame]
• Examples:
  • HR-Training-2024
  • Sales-Meetings-Q2
  • IT-Maintenance-Monthly

2. Department prefix implementation:

• Set up prefix system:
  1. Access calendar settings
  2. Edit calendar name
  3. Apply standard prefixes:
     • HR_ for Human Resources
     • IT_ for Information Technology
     • MKT_ for Marketing
     • FIN_ for Finance

3. Time period integration:

• Add relevant time indicators:
  • Include year: HR_Training_2024
  • Add quarter: Sales_Pipeline_Q2_2024
  • Specify month: IT_Projects_Jan2024

4. Name optimization:

• Follow naming best practices:
  • Maximum 30 characters
  • No special characters
  • Use underscores instead of spaces
  • Capitalize first letters

View customization:

Set up different views:

1. Go to “Calendar Settings” or “Calendar” ribbon at the top
2. Select “Create View”

3. Choose the type of view you want (Standard, Calendar, etc.).
4. Customize the view:
   • Daily/Weekly/Monthly: Choose the view type.
   • Filter: Set filters to display specific events.
   • Sort: Define how events are ordered.
   • Group By: Organize events by category or other fields.
   • Style: Choose a style for the view (e.g., default, boxed).
5. Name your view, choose whether it should be a public or personal view, and save the changes.

Event categories:

Here’s how to create categories, assign colors, and create filters: 

1. Create Category Names:
   

• Go to your calendar.
• Click on “List Settings.”
• Under “Columns,” add a new column named “Category.” (See Pic. 11)
• Choose “Choice” as the column type and enter your category names. 

2. Assign Colors to Categories:

• For SharePoint Classic, use a custom script or SharePoint Designer to apply CSS styles based on category names. This involves editing the calendar view page and adding custom styles. For SharePoint Modern, use JSON formatting to apply colors in list views.

3. Create Category Filters:
   

• Modify or create a view.
• In the view settings, use the “Filter” section to display items based on selected categories.

4. Documentation
   

• Create category guidelines:
  1. Open new SharePoint page
  2. Title: “Calendar Category Guidelines”
  3. Include:
     • Category definitions
     • Usage examples
     • Color references
     • Best practices

Remember to save all changes and test the display settings with different user accounts to ensure proper functionality across your organization. Regular reviews and updates of these settings will help maintain an effective calendar system.

Filter configuration

Here’s a detailed guide on working with filters in SharePoint Online:

1. Access calendar/list settings:

• Navigate to your calendar or list.
• Click on “List Settings” or “Modify View” from the ribbon.

2. Set up filters:

• In the view settings, scroll to the “Filter” section.
• Use logical conditions to filter items (e.g., show items when “Category” is equal to “Project”).

3. Date range filters:

• Use date columns to filter items within specific time frames.
• Create views for specific periods, like “This Week” or “Next Month.”

4. Category filters:

• Add a “Choice” column for categories.
• Filter views based on selected categories.

5. User and group filters:

• Use the “Filter” section to show items based on user roles or group membership.
• Use the [Me] filter to show items assigned to the current user.

Permission management

Proper permission management is crucial for calendar overlays, as it determines who can view, edit, and manage different calendar layers in your organization. Understanding how to set up and maintain these permissions ensures that sensitive calendar information remains secure while still being accessible to the right people. Let’s explore how to manage permissions in both SharePoint Online and On-Premises environments, each with their unique approaches to security and access control. 

👉  Here, we’ll cover the basics of both platforms’ permission systems, but for a more comprehensive understanding, check out our detailed article, Configuration & Management of SharePoint Permissions: A Complete Guide 2024.

Sharepoint Online calendar overlay permission management

We’ll start with a guide for managing permissions in SharePoint Online:

Admin center configuration

1. Access the Admin Center:
   • Go to the Microsoft 365 Admin Center.
   • Navigate to “Admin centers” > “SharePoint.”
2. Navigate to SharePoint settings:
   • In the SharePoint Admin Center, configure settings under “Policies” and “Active sites.”

3. Configure global permissions:
   • Set policies for sharing and access control at the tenant level.
   • Enable or disable external sharing as needed.
4. Set up security groups:
   • Use Microsoft 365 security groups to manage users.
   • Create groups in the Microsoft 365 Admin Center.

Group-based permissions

1. Create logical user groups:
   • Organize users into groups based on roles or responsibilities.
   • Use Microsoft 365 or SharePoint groups.
2. Assign appropriate permissions:
   • In SharePoint, go to a site > “Settings” > “Site permissions.”

• Assign permissions to groups.

3. Set up inheritance rules:
   • Decide whether sites inherit permissions from the parent site or have unique permissions.
4. Document permission structure:
   • Maintain a record of permissions for auditing and management purposes.

Sharing settings

1. Configure internal sharing options:
   • Set sharing settings in the SharePoint Admin Center to specify how content is shared internally.
2. Set up external sharing rules:
   • Define rules for sharing with external users and guests.
3. Manage guest access:
   • Enable or disable guest access at the site collection or tenant level.
4. Set up time-limited access:
   • Use policies to restrict the duration of access for external users.

External access management

1. Set up guest user accounts:
   • Invite external users through direct sharing links or guest invitations.

2. Configure external sharing links:
   • Create and manage sharing links via site settings or document libraries.
3. Manage security settings:
   • Regularly review and update security settings for external users.
4. Monitor external access:
   • Use the SharePoint Admin Center to monitor and audit external access activities.

Sharepoint On-Premises calendar overlay permission management

Here’s a guide for managing permissions in SharePoint On-Premises:

Central administration configuration

1. Access central administration:
   • Open the SharePoint Central Administration website.
2. Navigate to security settings:
   • Go to “Application Management.”
   • Click on “Manage web applications.”
   • Configure authentication providers and permissions policy levels.
3. Configure global permissions:
   • Set policies for web applications and site collections.
   • Define permission levels (e.g., Full Control, Contribute).

Group-based permissions

1. Create logical user groups:
   • Organize users into SharePoint groups based on roles.
   • Use Active Directory groups if integrated.
2. Assign appropriate permissions:
   • Go to “Site Settings” > “Site Permissions.”
   • Assign permissions to groups (e.g., Read, Edit).
3. Set up inheritance rules:
   • Choose whether sites inherit permissions from the parent site or have unique permissions.
   • Break inheritance if customization is needed.
4. Document permission structure:
   • Keep a record of permissions for auditing and management.

Sharing settings

1. Configure internal sharing options:
   • Use site permissions to manage internal sharing.
2. Set up external sharing rules:
   • Configure external access through web application policies, if needed.
3. Manage guest access:
   • Control guest access via site permissions and external sharing settings.
4. Set up time-limited access:
   • Implement policies manually to restrict the duration of access.

External access management

1. Set up guest user accounts:
   • Add external users through Active Directory or local accounts.
2. Configure external sharing links:
   • Manage sharing via site permissions and web application policies.
3. Manage security settings:
   • Regularly review security settings and permissions.
4. Monitor external access:
   • Use audit logs and reporting features in Central Administration to track access.

The steps above help ensure effective permission management and secure access to your SharePoint environment.

Mobile access

To set up mobile access to a SharePoint calendar, follow these steps:

SharePoint Online

1. Use the SharePoint mobile app:

• Download the SharePoint app from the App Store or Google Play.
• Sign in with your Microsoft 365 account.
• Navigate to the site containing the calendar.
• Access the calendar directly through the app.

2. Sync with Outlook:
   • Go to the SharePoint calendar.
   • Click on “Calendar” in the ribbon.
   • Select “Connect to Outlook.”
   • This syncs the calendar with Outlook, accessible from the Outlook mobile app.

SharePoint On-Premises

1. Access via mobile browser:
   • Open your mobile browser.
   • Navigate to your SharePoint site URL.
   • Use the mobile view for better usability.
2. Sync with Outlook:
   • Similar to SharePoint Online, connect the calendar to Outlook.
   • Access it via the Outlook mobile app.

👉  How do I create a calendar overlay in SharePoint? Creating a calendar overlay in SharePoint is a straightforward process. Start by opening your base calendar—this will serve as the foundation for your overlay. From there, access the overlay settings through the settings menu or ribbon, depending on your SharePoint version. Look for the “New Calendar” button to begin adding your overlay calendar. Once you click it, you’ll be presented with various configuration options where you can specify the calendar type and source. Take time to carefully choose your color and display settings; these visual elements will help users distinguish between different calendars in the overlay. Finally, don’t forget to save and publish your changes to make the overlay visible to other users. The whole process typically takes just a few minutes, and once set up, your overlay will provide a unified view of multiple calendars in one convenient location.

Exchange calendar overlay settings

Setting up Exchange calendar overlays varies significantly depending on whether you’re using SharePoint Online or On-Premises. Let’s briefly walk through both integration processes—from SharePoint Online’s streamlined, cloud-based approach to the more complex configuration required for On-Premises deployments. While SharePoint Online offers a more straightforward setup due to its native Microsoft 365 integration, On-Premises requires additional server-side configuration. Here’s how to implement Exchange calendar overlays in both environments:

SharePoint Online Integration

We’ve previously discussed how to add an Exchange calendar in SharePoint Classic, so let’s briefly recap. In Classic SharePoint, you navigate to your desired calendar and access the Calendar tab in the ribbon. From there, you select Calendar Overlay and proceed to add a new calendar. You’ll enter a name, choose Exchange as the type, and provide the email address of the Exchange calendar. If needed, you also enter the Exchange Web Service URL. Once everything is set, saving these settings will complete the overlay configuration (see Pic. 9). 

In contrast, Modern SharePoint does not support calendar overlays in the same way. However, you can use the following approaches:

1. Embed calendar using Outlook Web Access:

• Go to your Outlook calendar > “Settings” > “Calendar” > “Publish a calendar”.
• Get the sharing link (ensure it is set to allow view access).

• Use the Embed web part in SharePoint to display the calendar.

2. Use Power Automate or Power Apps: Create a Power App or Flow to pull calendar data and display it on a SharePoint page.
3. Third-party solutions: Consider third-party web parts or tools that offer calendar overlay functionality for modern SharePoint sites.

SharePoint On-Premises Integration

To integrate Exchange calendars in SharePoint On-Premises, several server requirements must be met:

1. First, ensure that Exchange Web Services (EWS) are configured on your Exchange server to allow seamless access. 
2. Next, install valid SSL certificates to secure communications between SharePoint and Exchange, ensuring data integrity and confidentiality. 
3. Additionally, verify that network connectivity between SharePoint and Exchange servers is properly established to facilitate uninterrupted data flow. 
4. Finally, create a dedicated service account with the necessary permissions for accessing Exchange calendars, providing a secure and efficient means of managing calendar data.

After meeting the server requirements, follow these steps to configure your Exchange calendar integration with SharePoint.

1. Configure Exchange service application:

• In SharePoint Central Administration, navigate to “Manage service applications.”
• Create a new Exchange service application and configure it with the EWS URL.

2. Set up a secure channel:

• Use HTTPS to establish a secure connection between SharePoint and Exchange.

3. Establish a trust relationship:

• Configure trust settings between SharePoint and Exchange to allow secure data exchange.

4. Configure authentication:

• Set up authentication methods, such as OAuth or basic authentication, depending on your environment.

Calendar overlay limitations and best practices

While SharePoint calendar overlays are powerful tools for schedule management, they do come with certain limitations that users should be aware of. In this section, we’ll explore these limitations and share best practices for both SharePoint Online and On-Premises environments. 

Calendar overlay limitations in SharePoint Online (Classic/Modern) and SharePoint On-Premises

In SharePoint Online, both Classic and Modern experiences have certain limitations when it comes to calendar overlays. In the Classic experience, you can overlay up to 10 calendars, but these must be from either SharePoint or Exchange. Each calendar overlay requires manual setup, and permissions must be correctly configured for each user accessing the calendars. Additionally, the interface can be less intuitive compared to modern solutions.

In Modern SharePoint, there’s no direct support for calendar overlays within the site itself. Users typically need to switch to a classic experience (as we’ve described in the beginning of the article), rely on embedding calendars, or use tools like Power Automate or Power Apps to display calendar data, which can be less seamless compared to direct overlays.

For SharePoint On-Premises, the limitations are similar to Classic SharePoint Online. You can overlay up to 10 calendars, and the setup process is manual. On-Premises environments may also face additional constraints related to server performance, maintenance, and updates, which can affect how well calendar overlays function.

Overall, while calendar overlays offer a way to consolidate multiple calendars, the setup and management can be cumbersome, and users might need to seek alternative solutions or workarounds in certain scenarios.

👉 Interested in learning more about SharePoint limitations? Then head to the dedicated article on our blog: The Ultimate Guide to SharePoint Limitations in 2024: Online vs On-Premises

Best practices for working with multiple overlaid calendars

In this section, we’ll briefly explore best practices for managing multiple overlaid calendars in SharePoint Online (Classic and Modern) as well as SharePoint On-Premises. These guidelines will help ensure a more organized and efficient calendar experience across different platforms:

1. SharePoint Online (Classic)

• Limit overlays: Keep the number of overlaid calendars to a minimum to avoid clutter and confusion.
• Color coding: Use distinct colors for each calendar to easily differentiate between them.
• Consistent naming: Use clear and descriptive names for each calendar overlay.
• Permissions management: Ensure that users have the necessary permissions to access all overlaid calendars.
• Regular updates: Keep calendar entries updated to maintain accurate scheduling information.

2. SharePoint Online (Modern)

• Use alternatives: Consider embedding calendars Outlook Web Access, leveraging Power Automate and Power Apps to display data, or integrating third-party solutions like Virto Calendar App for SharePoint and Microsoft 365.
• Integrate with Microsoft 365: Utilize Microsoft 365 tools for better integration and functionality.
• User training: Provide training on how to access and use embedded or integrated calendars effectively.

3. SharePoint On-Premises

• Optimize performance: Regularly monitor server performance to ensure calendars load efficiently.
• Backup calendars: Maintain regular backups to prevent data loss.
• Consistent configuration: Ensure all calendars are configured similarly for ease of use and management.

Common issues and solutions

While we’ve discussed some of these issues earlier, here’s a tabular format for easy reference.

Platform	Common issue	Solution
SharePoint Online (Classic)	Cluttered view	Limit the number of overlaid calendars and use color coding to differentiate them.
	Permissions errors	Ensure correct permissions are set for all users accessing the calendars.
	Slow performance	Regularly clear browser cache and optimize calendar data for faster loading.
SharePoint Online (Modern)	No direct overlay support	Use embedding via Outlook Web Access, third-party solutions like Virto Calendar App, or tools like Power Automate to display calendar data.
	Integration challenges	Leverage Microsoft 365 integration options to enhance calendar functionality.
	User confusion	Provide training and clear documentation on accessing and using embedded calendars.
SharePoint On-Premises	Server performance	Monitor and optimize server resources to ensure efficient calendar operations.
	Configuration inconsistencies	Standardize calendar settings and regularly review configurations.
	Data backup concerns	Implement regular backup procedures to prevent data loss.

👉 So, how many calendars can you overlay in SharePoint? SharePoint allows up to 10 calendar overlays per view. This limit applies to both SharePoint Online and On-Premises versions. When managing multiple calendars, it’s recommended to group related calendars and implement a clear organization system to maximize the effectiveness of the overlay feature.

Setting Up Color Coding and Customization for Overlays in SharePoint

Earlier, we discussed basic strategies for color coding calendar overlays. Now, let’s explore some of these options in detail for different SharePoint versions, along with additional features to enhance your calendar’s visual organization. While some features may overlap with our previous discussion, this section will provide additional commentary for better understanding and implementation.

The power of visual organization

Color coding in calendar overlays isn’t just about aesthetics; it’s a powerful tool for information management. When implemented effectively, color coding can:

• Reduce time spent searching for specific events
• Minimize scheduling errors
• Improve team coordination
• Create intuitive visual hierarchies
• Enable quick identification of different calendar types

How to customize overlay colors

While the modern interface offers the most straightforward and comprehensive customization tools, on-premises version have their own approaches to color coding and visual organization. 

SharePoint Online

In SharePoint Online’s modern interface, customizing color coding is straightforward:

1. Navigate to your calendar settings ribbon menu
2. Choose the “Calendars Overlay” option, and assign a distinct color to each calendar (See Pic. 6)

This feature helps maintain a clear visual distinction between different calendar events.

When standard options aren’t enough:

• Use SharePoint Designer for advanced customization
• Implement custom CSS solutions
• Add JavaScript enhancements
• Create custom web parts

SharePoint On-Premises

Customization in SharePoint On-Premises can vary depending on your version. Some versions offer limited color options and may require additional steps from an administrator. It’s important to check your version’s documentation and potentially involve IT support for advanced customization.

Design templates for calendars

Creating design templates for calendars can standardize the appearance and improve coherence across multiple calendars. By setting a consistent style, users can quickly adapt to viewing multiple overlays without confusion.

Here are instructions for creating a design template across different SharePoint versions:

SharePoint Online (Classic)

1. Access the calendar:
   • Navigate to your SharePoint site and open the calendar you want to modify.
2. Calendar settings:
   • Click on the Calendar tab in the ribbon.
   • Select “List Settings” (See Pic. 5)
3. Modify the view:
   • Under Views, choose the view you want to modify (e.g., Calendar view).

• Customize the view by selecting Change Style to choose a layout.

4. Set colors and fonts:
   • Unfortunately, direct color customization for calendars is limited in Classic. You can use custom CSS via a script editor web part for additional styling if needed.
5. Save as template:
   • Go back to List Settings and click Save list as template.
   • Provide a name and description, then save.

SharePoint Online (Modern)

1. Access the calendar: Go to your SharePoint site and access the calendar.
2. Customize using Power Apps:
   • Modern SharePoint uses Power Apps for advanced customization.
   • Click on Integrate > Power Apps > Customize Forms.
3. Design the form:
   • Use Power Apps to design your form by adding controls and setting styles.
   • Save and publish your changes.
4. Apply consistent styles:
   • Use the site’s theme settings to apply consistent colors and fonts.

SharePoint On-Premises

1. Access the calendar:
   • Open your SharePoint site and navigate to the calendar.
2. Calendar settings:
   • Click the Calendar tab and choose List Settings.
3. Modify the view:
   • Under Views, select the view you wish to modify.
   • Adjust settings to change the layout and appearance.
4. Advanced customization:
   • Use custom CSS or JavaScript for more advanced styling. This might require modifying the master page or using a script editor web part.
5. Save as template:
   • Within List Settings, select Save list as template.
   • Name and save your template for reuse.

Conditional formatting

Using conditional formatting allows you to highlight certain events based on specific criteria. 

Here’s how you can apply conditional formatting to calendars in SharePoint to highlight specific events:

SharePoint Online (Modern)

1. Access the calendar:
   • Go to your SharePoint site and open the calendar list.
2. Use JSON Formatting:
   • Navigate to the calendar view.
   • Click on the view name and select Format current view.
   • Choose Advanced mode and use JSON to apply conditional formatting.
3. JSON Example:
   • You can use JSON code to change the color of events based on criteria like priority. For example:

{

  "schema": "https://developer.microsoft.com/json-schemas/sp/view-formatting.schema.json",

  "additionalRowClass": "=if([$Priority] == 'High', 'sp-row-override', '')"

}

• Customize the JSON code based on your specific criteria and styling needs.

2. Apply and save:
   • Click Save to apply the formatting.

SharePoint Online (Classic)

1. Access the calendar:
   • Navigate to your calendar on the SharePoint site.
2. Customize the view:
   • In the ribbon, click on “List Settings”.
   • Under Views, select the view you want to modify.
3. Use Custom JavaScript/CSS:
   • Conditional formatting is not directly supported, but you can use a script editor web part to inject JavaScript/CSS for custom coloring.
   • Example JavaScript might check for specific event properties and apply styles dynamically.

SharePoint On-Premises

1. Access the calendar:
   • Open your SharePoint site and go to the calendar list.
2. Use JavaScript/CSS:
   • Similar to Classic SharePoint Online, use a script editor web part to apply custom styles.
   • Write JavaScript to evaluate event properties and apply conditional styles.
3. Custom solutions:
   • Consider using SharePoint Designer workflows to set up conditions and apply styles indirectly by setting fields that can be used in view formatting.

By using these techniques, you can effectively apply conditional formatting in SharePoint calendars to enhance visual organization and prioritize important events.

👉 How do you overlay calendars? To overlay calendars in SharePoint Classic, go to the calendar, click the “Calendar” tab on the ribbon, and select “Calendar Overlay.” Add a new calendar by entering the name, type (SharePoint or Exchange), and email address if applicable. In SharePoint Modern, use the Embed web part or Power Automate to pull and display calendar data, as direct overlays aren’t supported. Make sure permissions are set correctly for all users accessing these calendars.

Additional Capabilities for Working With Calendars in SharePoint: Virto Calendar App for SharePoint Online & Microsoft 365 and Virto Calendar Web Part for SharePoint On-Premises

As we’ve seen throughout this article, SharePoint’s native calendar overlay functionality comes with significant limitations. From the restriction of only 10 overlaid calendars to the complex color-coding process, and especially the challenging setup in On-Premises environments, many organizations find themselves needing more robust solutions. Add to this the requirement for JSON, CSS, and administrative rights for certain features, and what should be a straightforward task can quickly become overwhelming.

Fortunately, there are alternative solutions designed specifically to address these limitations. Let’s explore how Virto Calendar solutions can enhance your SharePoint calendar experience.

Virto Calendar App for SharePoint Online & Microsoft 365

The Virto Calendar App transforms how you manage calendars in SharePoint Online by offering a more intuitive and powerful approach to calendar overlays:

1. Enhanced data integration

• Seamless overlay of Exchange Online calendars with Microsoft 365 calendars
• Direct integration with SharePoint lists for event and task display
• Support for external calendars through iCal links (including Google Calendar)
• Meeting room calendar integration
• Microsoft Planner task integration
• Public folder calendar support

2. Advanced visualization

• Unlimited calendar overlays, breaking free from SharePoint’s 10-calendar limit
• Flexible timeline views (day, week, month, year, flat year, tasks)
• Intuitive color-coding system without requiring technical knowledge
• Mini calendar feature for quick overview
• Clear event categorization

Virto Calendar Web Part for SharePoint On-Premises

For organizations using SharePoint On-Premises, the Virto Calendar Web Part offers similar powerful functionality while addressing the specific challenges of on-premises environments:

1. Comprehensive data source integration

• Multiple calendar source support (Google Calendar, Outlook, SharePoint Lists)
• SQL table integration
• XML data source support
• Custom data source configuration

2. User-friendly interface

• Multiple view options (Day, Year, Month, Week, Work Week)
• Event tooltip previews
• Advanced search functionality
• Role-based calendar customization

Comparing native SharePoint vs. Virto Calendar Solutions

Let’s look at how Virto Calendar solutions address common SharePoint limitations:

Feature	Native SharePoint	Virto Calendar
Calendar overlay limit	10 calendars maximum	Unlimited overlays
Color coding	Limited, requires technical knowledge	Intuitive, user-friendly interface
Cross-platform integration	Limited	Extensive support for multiple platforms
Setup complexity	Often requires admin rights	User-level configuration
Customization	Requires technical skills (JSON, CSS)	Built-in customization tools
Mobile responsiveness	Limited	Fully responsive design
Event management	Basic	Advanced tools and features

Solving common user problems

Virto Calendar solutions have been specifically designed to address the most pressing challenges that organizations face when managing calendars in SharePoint. Let’s explore how these solutions tackle key problem areas and transform calendar management for teams of all sizes.

Large team management

Managing calendars for large teams presents unique challenges that native SharePoint solutions often struggle to handle. Virto Calendar solutions excel in this area by providing robust tools for complex organizational structures.

When dealing with multiple department schedules, managers can easily create department-specific views while maintaining a unified calendar system. For example, a manufacturing company can simultaneously track production schedules, maintenance rotations, and staff shifts without overwhelming users with irrelevant information. The system efficiently handles hundreds of concurrent events, making it ideal for organizations with multiple teams and projects running simultaneously.

The optimized performance ensures that even with dozens of overlaid calendars, the system remains responsive and reliable. This is particularly valuable for organizations like educational institutions that need to manage multiple course schedules, faculty availability, and facility bookings simultaneously.

Role-based access control allows administrators to precisely manage who can view and edit specific calendars. For instance, department heads can have full access to their team’s schedules while maintaining limited visibility of other departments’ calendars, ensuring both transparency and privacy where needed.

Visual organization

Clear visual organization is crucial for effective calendar management, and Virto Calendar solutions offer sophisticated tools for creating intuitive, easy-to-navigate calendar systems.

The color-coding system goes beyond basic categorization, allowing organizations to create meaningful visual hierarchies. For example, project managers can assign different colors to various project phases, making it immediately apparent how different activities relate to project timelines. Marketing teams can color-code different campaign activities, making it easy to track multiple campaigns simultaneously.

Event categorization is designed to be intuitive, allowing users to quickly organize and filter events based on custom categories that make sense for their specific needs. Whether it’s categorizing events by priority, department, or project phase, the system adapts to your organization’s unique requirements.

Multiple view options accommodate different working styles and needs. Users can switch between daily, weekly, monthly, and custom views, each optimized for specific use cases. For instance, executives might prefer a monthly overview for strategic planning, while project managers might rely on detailed weekly views for day-to-day coordination.

Accessibility

Modern organizations require calendar solutions that work seamlessly across different platforms and devices, and Virto Calendar delivers comprehensive accessibility features.

Cross-platform compatibility ensures that whether team members are using desktop computers, tablets, or smartphones, they have consistent access to their calendars. This is particularly valuable for organizations with remote workers or field teams who need to access and update calendars on the go.

The mobile-friendly interface is designed specifically for smaller screens, maintaining functionality without sacrificing usability. Users can easily view, create, and modify events from their mobile devices, ensuring that calendar management isn’t tied to a desk.

Navigation has been streamlined to be intuitive across all platforms. Users can quickly jump between dates, switch views, and find specific events without extensive training. The search functionality is powerful yet simple to use, allowing users to quickly locate events across multiple calendars.

Quick event preview functionality allows users to get essential information about events without having to open full event details. This is particularly useful in mobile contexts or when quickly scanning for schedule conflicts. Hovering over an event reveals key details like time, location, and participants, speeding up calendar navigation and decision-making.

By addressing these common challenges, Virto Calendar solutions transform SharePoint calendar management from a potentially frustrating experience into a streamlined, efficient system that enhances organizational productivity and team coordination.

Conclusion

Throughout this article, we’ve explored how SharePoint calendar overlays can help teams coordinate schedules, manage events, and improve overall productivity. From basic setup to advanced customization, we’ve seen that while SharePoint’s native calendar features provide a foundation for calendar management, they also come with notable limitations.

The ability to combine multiple calendars into a single view is undeniably powerful, offering teams a comprehensive overview of schedules across departments, projects, and individual team members. However, as we’ve discussed, the native SharePoint calendar overlay system presents several challenges. The limit of ten overlaid calendars, restricted color-coding options, and complex setup requirements—particularly in On-Premises environments—can hinder rather than help organizational efficiency.

This is where solutions like the Virto Calendar App for SharePoint Online & Microsoft 365 and Virto Calendar Web Part for SharePoint On-Premises become invaluable. These tools extend SharePoint’s native capabilities, offering unlimited calendar overlays, intuitive color coding, and seamless integration with various calendar sources. Whether you’re managing a small team or coordinating across a large enterprise, these solutions provide the flexibility and functionality needed for effective calendar management.

For organizations seeking to optimize their calendar management strategy, consider how Virto Calendar solutions can enhance your team’s collaboration and scheduling efficiency. The ability to integrate multiple data sources, customize views, and manage large-scale calendar overlays without technical complexity makes these tools particularly valuable for growing organizations.

We encourage you to explore these solutions further by:

• Scheduling a quick demo call with one of our team members
• Installing a free 14-day trial version of Virto Calendar App for SharePoint Online
• Installing a free 14-day trial version of Virto Calendar Web Part for StarePoint On-Premises

For those interested in learning more about calendar management in SharePoint and Microsoft 365, we invite you to explore these additional resources:

Official Microsoft documentation:

• Overlay a SharePoint calendar with Exchange or SharePoint calendars
• Microsoft Community Discussion on Calendar Overlays

Related VirtoSoftware blog articles:

• Managing Multiple Microsoft 365 Calendars
• Complete Guide to Merging and Combining Calendars