Subscribe to iCal times off by 2 hrs in outlook.com/outlook(new) vs Thunderbird

Larry R 0 Reputation points
2026-09-14T22:11:41.7566667+00:00

I have all my TZ set to my correct TZ. I created a new fresh iCloud calendar and made it public.
In Mozilla Thunderbird I replace the URL protocol to https from webcal to https and which Mozilla TB loads the correct times. But when I do the same thing in outlook.com the time is off by 2 hours. The TZID shows my timezone when I inspect the ICS file...

Ideas why outlook is not displaying the correct TZ whereas TB is?

I am subscribing to the web iCloud calendar and not using the ICS file directly.

Thanks!

Outlook | Web | Outlook.com | Calendar
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  1. Chloe-V 12,790 Reputation points Microsoft External Staff Moderator
    2026-09-15T04:26:46.95+00:00

    Hi @Larry R

    Since the same iCloud calendar displays the correct times in Thunderbird but is consistently two hours off in Outlook.com and new Outlook, this appears to be related to how Outlook interprets the calendar’s time-zone or daylight-saving information.

    Please note that this is a user-to-user support forum. Moderators, contributors including external Microsoft employees cannot directly intervene in Microsoft product features or access back-end systems. Our role is limited to providing technical guidance on reported issues, requests, or ideas only.

    Please first verify the time zone in Outlook.com under Settings > Calendar > View > Time zones, making sure that the correct city-based time zone is selected rather than a fixed UTC offset. Outlook stores calendar times in UTC and converts them according to its configured time-zone rules.

    After that, remove the subscribed calendar, add it again using Calendar > Add calendar > Subscribe from web, and test with a newly created event. Please note that subscribed calendar updates may take more than 24 hours to appear.

    If the two-hour difference remains while Thunderbird continues to display the same subscription correctly, I recommend contacting Microsoft Support and providing a sample of the affected event’s DTSTART, DTEND, TZID, and VTIMEZONE entries, with any personal information removed.

    Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.  

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