Shared Calendars are showing inconsistent/wrong times on Outlook Calendar Classic

Hi @Julian Martinez,

Thank you for posting your question in the Microsoft forum.

From your screenshot, the tooltip shows 9:00–10:00 AM, but the block is drawn at ~4:30 AM. This usually points to a time‑zone setting or a cached view/profile issue in Classic Outlook for Windows.

You can try to follow these steps in order and stop as soon as the calendar grid and tooltip match:

Step 1: Verify Windows time settings

Outlook relies on Windows time. Make sure it’s correct:

1/ Open Settings > Time & language > Date & time.

2/ Turn Set time automatically On.

3/ Turn Set time zone automatically On (or manually select the correct zone).

4/ Keep Adjust for daylight saving time automatically On if applicable.

5/ Restart Outlook and check the calendar.

Step 2: Confirm Outlook’s time zones

Classic Outlook can show two zones on the left ruler.

1/ Go to File > Options > Calendar.

2/ Under Time zones:

• Ensure the primary zone is correct.
• If a second zone is enabled, confirm its label and offset.
• As a test, uncheck “Show a second time zone,” click OK, and reopen the calendar.

3/ Re‑enable the second zone later if needed.

You can see: Manage time zone settings in Outlook

Step 3: Check Outlook on the web (OWA)

This isolates mailbox settings.

1/ Sign in to OWA.

2/ Go to Settings > General > Language and time.

3/ Confirm the time zone matches Windows/Outlook.

4/ Open the same shared calendar:

• If OWA shows correct placement then it's local cache issue.
• If OWA is off, fix the OWA time zone.

You can see: Time zone and language settings in Outlook Web App

Step 4: Reset the calendar view

Corrupted views can misplace items.

• In the calendar, select View > Reset View.

• If multiple shared calendars exist, repeat for each.
• If still wrong, close Outlook and run: outlook.exe /cleanviews

You can see: Change how you view your Outlook calendar

Step 5: Start Outlook in Safe Mode

Rules out add‑ins.

1/ Close Outlook.

2/ Press Win + R, run:

outlook.exe /safe

3/ If correct in Safe Mode, disable non‑Microsoft COM Add‑ins under: File > Options > Add‑ins > COM Add‑ins > Go….

You can see: Open Outlook in safe mode

Step 6: Rebuild the local cache (OST)

If OWA is fine but Classic Outlook persists:

1/ File > Account Settings > Data Files tab.

2/ Select the .ost file > Open File Location

3/ Close Outlook, rename the file (e.g., account-old.ost).

4/ Restart Outlook to rebuild the cache.

You can see: Repair Outlook Data Files (.pst and .ost)

Step 7: Re‑add the shared calendar (modern sharing model)

Legacy sharing can cause time‑zone quirks.

1/ Owner: In OWA, go to Sharing and permissions, re‑share the calendar.

2/ Recipient: Accept in OWA, then remove and re‑add in Classic Outlook via: Home > Add Calendar > Open Shared Calendar….

You can see: Shared calendars updates in Outlook for Windows

Step 8: Update Office

Calendar rendering bugs are fixed in updates.

• File > Office Account > Update Options > Update Now.

You can see: Update Office

Step 9: Create a new Outlook profile

If corruption persists, you can follow this: Create new Outlook profile

Please understand that our initial response does not always resolve the issue immediately. However, with your help and more detailed information, we can work together to find a solution. 

I hope this information is helpful. Please follow these steps and let me know if it works for you. If not, we can work together to resolve this. 

Thank you for your patience and your understanding. If you have any questions, please feel free to reach out. 

I'm looking forward to your reply. 

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