In our company the Thunderbird calendar meeting invitations are off by an hour. Refer to screenshots where it shows the current time in Windows is 7pm but the time in Thunderbird is 8pm. Condition found: Thunderbird time is 8pm. In the screenshot with the calendar view you can see in the bottom right hand corner Windows indicates it's 7pm but the red time indicator in the Thunderbird calendar view is 8pm. Desired condition: Thunderbird time should match Windows time of 7pm. Please note that: Mexico observed summertime daylight saving time starting in 1996. In late 2022, the nation's clocks "fell back" for the last time, in restoration of permanent standard time. [[https://en.wikipedia.org/wiki/Daylight_saving_time|https://en.wikipedia.org/wiki/Daylight_saving_time]] Things tried: Installed the latest Thunderbird on fresh Windows machine. Googled: [[https://www.google.com/search?q=thunderbird+calendar++not+respecting+time+mexico+standard+time+2023|Google Search]] Does anyone see what I might be doing wrong?