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Thunderbird Calendar Date Format Unwanted Change

  • 2 replies
  • 0 have this problem
  • 37 views
  • Last reply by dsshaw033

dsshaw033
dsshaw033
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My Thunderbird Calendar has started displaying time in 24-hr format (HH:mm), while by Thunderbird eMail continues to display the ‘am/pm’ format (hh:mm tt), correctly using my laptop’s Windows 10 System format, as shown in Control Panel/Region/Formats tab. I’d like to get Calendar back to hh:mm tt, without loosing all my calendar data. I suspect the problem was caused by an interruption when downloading the latest Thunderbird update, so I’ve tried manually downloading and installing a fresh copy of Thunderbird Setup 102.0.3, but the time display format wasn’t fixed. Is there a reliable way to roll back to the previous version without losing what I’ve added to my calendar between the time this format change occurred and the time I first noticed the change?

My Thunderbird Calendar has started displaying time in 24-hr format (HH:mm), while by Thunderbird eMail continues to display the ‘am/pm’ format (hh:mm tt), correctly using my laptop’s Windows 10 System format, as shown in Control Panel/Region/Formats tab. I’d like to get Calendar back to hh:mm tt, without loosing all my calendar data. I suspect the problem was caused by an interruption when downloading the latest Thunderbird update, so I’ve tried manually downloading and installing a fresh copy of Thunderbird Setup 102.0.3, but the time display format wasn’t fixed. Is there a reliable way to roll back to the previous version without losing what I’ve added to my calendar between the time this format change occurred and the time I first noticed the change?

All Replies (2)

Toad-Hall
Toad-Hall
  • Top 25 Contributor
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I'm using Windows 10 and Thunderbird 102.0.3 I did have computer and therefore Thunderbird all using 24 hour.

re :as shown in Control Panel/Region/Formats tab.

I check that location on my computer and I have:

  • Short time: h:mm tt
  • Long time: h:mm:ss tt

However, Windows OS has two locations for setting up date/time etc. As you have the correct settings in the Control Panel/Region/Formats tab Please check the other method just in case something is out of synch with Windows. I have known this to occur before.

  • In windows bottom search type: 'Date time' and selected 'Change the date and time'
  • select : 'Date, Time and regional formatting'
  • select 'Change data formats'

Please work through each one, maybe select one you do not want eg:24 hr and then reset to one you want to use as below.

  • Set short time as : eg: 9:40 AM
  • Set Long time as: eg: 9:40:07 AM

Note: Computer clock in bottom right changed to match selection.

Exit Thunderbird. Wait a few moments and then restart Thunderbird.

In my case result: all email and everything in calendar was now on the AM/PM 12 hour clock.

dsshaw033
dsshaw033 Question owner
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This didn't solve my problem, but two Thunderbird updates later did fix it!