> Obviously even UTC for a location varies depending on the time of year.
The offset from UTC for a location varies depending on time of year but UTC definitionally has a zero offset throughout the year.
If you’re in the Europe/London time zone your time is equal to GMT/UTC (offset zero) for half the year and BST (offset +1) for the other half.
In other words we have two different types here: Timezones based on location where the UTC offset varies, and the UTC offset itself (like +0100/BST or +0000/GMT/Z.)
I remember getting yelled at by an American on Reddit once, when I asked what they meant by EST. Because of course America is the only country that shouldn't have to use country-prefixed versions of anything.
And of course, saying 'EST' doesn't actually tell me what fucking time something is happening. Telling me what UTC offset EST is, does.
Timezones are such a headache. Obviously even UTC for a location varies depending on the time of year.
Even the International Space Station shifted timezones from Houston time to UTC+0.
Curiosity and Perseverance's clocks are UTC but operations run on LMST (local mean solar time) Gale Crater and LMST Jezero Crater- their landing locations. That point is moot until humans start spinning up VMs on Mars which they will one day.