Questions about time zones

We're looking at using time zones in a sensible way. I have seen a couple of very old topics on time zones here already, but it's not clear if they were resolved eventually or not.

My questions, both for all you brilliant users and for @XTRF:

- Can vendors set their time zones in the Vendor Portal? I couldn't really see that option, but maybe I didn't look in the right place.

- Are deadlines and other specified dates/times automatically 'recalculated' and displayed in the recipient's time zone (VP jobs, Client Portal, POs, quotes, other documents)?

- Is there a way to take time zones into account when automatically sending availability requests (Classic Projects)?

- There is the default setting of working hours for vendors - does that take different time zones into account, or is it based on system time zone?

Greatly appreciate all your insights and experiences.