Your timezone tells Timely what your published hours mean. A player in another country sees those same hours converted to their own local time, so neither of you has to do the arithmetic.

Open your availability settings. The timezone selector sits above the weekly hours.
Availability settings
Choose the zone you actually teach in, not the one your laptop is set to.
Save before you edit any hours.

Set this before you publish hours. Changing your timezone reinterprets every slot you have already published, which can move lessons relative to your day.

Set your teaching weekPublish the hours you teach once, and let the schedule enforce them.
Session length, buffers and noticeThe four rules that decide which of your open hours a player is actually offered.

Next