Network calendar events are off by 1 hour
Thunderbird's Calendar displays time for events from Google's calendar (probably other network calendars too) incorrectly. For example, i create an event with "New Event", select "Calendar: <my gmail account>" and set "Start: 15:00", "End: 16:00", then "Save and Close". Thunderbird Calendar displays it as from 16:00 to 17:00. "Use system timezone" is selected in Calendar settings. When i open "Edit" dialog for the event, time in "Start:" and "End:" fields is also incorrect (16:00 and 17:00 respectively). However, when i go to "Options" and click "Show Timezones" it becomes correct (15:00 and 16:00). Disabling "Show Timezones" leads back to incorrect time. Web page and other applications display time for the same event correctly (as i set it during creation). The same error for events created not by Thunderbird but on web page or other applications. Thunderbird 115.9.0.
Wšě wotmołwy (3)
Another Linux user.
I suggest you have a look at what timezone your system is actually using. Recently I have seen folk using Wayland I think that have a Timezone for the GUI and one for the operating system. I am guessing one of yours is not correct.
Timezone in my OS is correct. System RTC is in UTC, /etc/localtime points to correct timezone file (currently GMT+3). No any time issues observed neither in X applications (except Thunderbird's Calendar) nor in console. I'm not using Wayland, just Xorg and Fluxbox window manager. Also created event time is displayed correctly on Google's calendar web page and in smartphone application.
It looks like Thunderbird Calendar ignores Daylight Saving Time. If i run `TZ=UTC thunderbird` everything is fine. If i change system time back when DST isn't applied, everything is fine. And seems the issue emerged after my timezone switched to DST.