Unable for multiple users to add Items to a Calendar on Sharepoint.

Dear @Peter Grimmett,

Thank you for posting your question in the Microsoft Q&A forum!

First of all, I want to begin by sincerely apologizing for the frustration and inconvenience this issue has caused you.

According to your description, I understand that you have already configured the permissions and ensured that the filters are set correctly.

To help me investigate this further, could you please share screenshots of your current settings for my review?

In my test environment, when a user adds an item to the SharePoint Calendar, the item is displayed correctly in the Month, Week, and Day views. Other users are also able to view these items without any issues. As a result, I’m currently unable to reproduce the same behavior you’re experiencing.

In this case, I recommend comparing your configuration with the settings in my test environment above and verifying whether your Calendar is configured in the same way.

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Please feel free to reach out if you have any questions or need further clarification. Your understanding and co-operation are highly appreciated.

I am looking forward to your response!

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In a SharePoint calendar, what appears in the Monthly view is controlled entirely by the view configuration, not by who created the item. Since items from other users appear in “All Items” and sometimes in Weekly view, the issue is almost certainly with the Monthly view settings.

Check and adjust the following on the calendar’s Monthly view:

1. Verify permissions

• Ensure all users who should add items have at least Contribute (or “Edit Items”) permission on the calendar list. Without this, items may not be saved correctly.

2. Check the Monthly view filters

• Go to the calendar list.
• On the ribbon, select Calendar > List Settings.
• Under Views, select the Month (Monthly) view.
• In the Filter section, confirm there is no filter that restricts items to a specific creator (for example, Created By is equal to [Me]) or other criteria that would exclude items created by others.
• If such a filter exists, remove it or adjust it so all relevant items are included.

3. Check the Monthly view scope and date fields

• In the same Monthly view settings, verify that:
  • The Calendar Columns are correctly set (e.g., Begin and End date fields are mapped to the correct columns).
  • There are no Group By or Sort settings that could hide or collapse items unexpectedly.

4. Confirm items are in the same calendar

• Ensure users are adding items to the same calendar list that the Monthly view is based on (not to a different calendar or overlay).

5. If using overlays or Aggregated Business Calendar Web Part

• If the calendar is shown through an Aggregated Business Calendar Web Part, edit the Web Part and verify:
  • The correct SharePoint calendar is selected in Available SharePoint Calendars.
  • The Available Views setting for that calendar is the Monthly view intended for all users.
  • Users have permission to view the source calendar; otherwise, entries will not appear in the aggregated view.

After adjusting the Monthly view filters and confirming permissions, items created by other users should appear consistently in the Monthly view.

References:

• Add and use an Aggregated Business Calendar Web Part
• Use a Group Calendar