Can you clarify a point. Are you talking about the 'Today Pane' which can be enabled on the right side? The 'Today Pane' can be viewed whether you are viewing in 'Calendar' tab or 'Tasks' tab or even when those tabs are closed. One of the options is to view the 'Events & Tasks' in the 'Today Pane'.

Are you saying that if you leave computer on and Thunderbird running and it goes past midnight, the 'Today' date is not auto progressing to show the correct date ?

Does this occur regardless of whether you view via 'Calendar' tab or 'Tasks' tab or when those tabs are closed? Does it occur only if you have one of the Lightning tabs open?

Other than Lightning, what other addons do you have installed ?

Thank you for your message. I'm talking about right pane containing Tasks and Events areas, and the date. Yes, you are correct. When Thunderbird is running and it goes past midnight the date doesn't change to current one. Yes, this situation doesn't depend on opened tabs. Date pane remains unchanged. And Lightning is opened all the time as I need info about coming events and tasks to do. Besides Lightning I've installed LightningButton and CompactHeader addons. Regards, Paweł

re :installed LightningButton and CompactHeader addons. Would you run a test over night to ensure no addons are causing a conflict and report back on results.

Yes I would, but would you explain what do you mean by test. What should I do to get results you want? Would simple disabling them do?

re :Would simple disabling them do?

yes that would be ok.

I'm trying to gather data for a bug report, but developers would need to know that nothing else is interfering to prove it really is a bug and not caused by a conflict.

It's 1 am my time. Nothing changed. The date is still the yesterday's one. Restarting Thunderbird to get correct date, and then restarting addons to revive them.

OK thanks for info.

What version of Thunderbird are you using? The most up to date is version is 68.4.2

If you are not using 68.4.2, can you update thunderbird and tell me if you still have the problem with date.

I'm using 64-bit version 68.4.2.

I've forgotten to mention one thing: To the right of date there are three symbols (< o >) that theoretically can be used to change the date. Unfortunately none of this symbols work. I can't change date using them.

Could you check this query and report back on your setup. Q: Is Lightning's timezone set to something different from the computer system timezone?

Q:What is your computer system timezone and what is the timezone in Lightning ?

If you update to current version 68.5.0 does the issue appear to get fixed?

1. I've tried to find the Lightning timezone, but failed. Where is ti? I suppose that it's the same as the system one. Meaning CET. 2. I've updated to current version, restarted Thundrbird, and nothing changed. Sorry.

Menu app icon > Options > Calendar > 'General' Timezone: Select the closest city in your timezone.

Example: My computer Windows 10 OS: 'Date & time' > 'Timzone' is (UTC+00.00) Dublin, Edinburgh, Lisbon, London) Adjust for daylight saving time automatically is set to 'On'.

In Thunderbird, my timezone city is 'Europe/London'.

What exactly have you set computer timezone to say and what do you have selected Calendar timezone?

Calendar timezone is "Europe/Warsaw". System timezone is "(UTC+1:00) Sarajewo, Skopje, Warszawa, Zagrzeb".

Another user had same issue and the update fixed their problem. Sadly, not in your case.

Current version 68.5.0. Would you try uninstalling the program (not the profile) and downloading and installing a fresh copy from this link: https://www.thunderbird.net/en-US/thunderbird/all/ If you are using Windows OS, I suggest you download the 'windows32bit' option.

Sorry for the delay, but I was a bit busy. I have no good news for you. I've uninstalled the program and downloaded and installed a fresh copy from the link provided, restored appropriate profile, but nothing changed.