Oh I meant bets, but timezone is irrelevant, whatever the time stamp says on block 420,000
The time stamp is a number. A timezone is needed to convert a number to a date.
Ok if you want to argue semantics, the time stamp is a UNIX time code which corresponds to Coordinated Universal Time (also known as Zulu time if you are in the Navy) which is largely aligned with Greenwich Mean Time (GMT). So that is the time zone.