"today" calculated relative to UTC rather than system time

[MatiasWettstein]

Can we define the default time zone for the calendar?

For example, in the calendar, I have the "today" part, but in my case, I need to set the default TZ at UTC-3, because it detects the next day at 9:00 PM of the current day.

Is this something that is planned to be implemented into cally?

Thanks!