Log into your Microsoft account and open your calendar. Select Settings, then select Time Zone to make sure your time zone is correct. If your calendar is part of Office 365, select Show in Time Zone to make sure it is set correctly.

Ensure events are set for the right date. Scroll through the calendar to quickly review the dates and update any that do not match.

If you have multiple Office 365/Exchange accounts linked to the same Microsoft account, make sure events created in one account are not appearing in others. You can separate multiple accounts by creating a new profile in Windows 10.

Review the Office 365 Admin Message Center for any known issues related to calendar or event syncing. You can also check Microsoft's 365 status page.