Should time zones start from east to west or west to east?

Answer 1

Timezones are not "Numbered" - that is, they are NOT assigned some arbitrary ranking. So, Pacific Time is not "before" or "after" Moscow Time in some ordering method. The question implies that we start at some point and count up from there in one direction, which is NOT the case.

Rather, timezones indicate an offset from a standard starting point - in this case, from the zone containing Greenwich, UK. This particular starting zone was chosen not for any special natural reason, but because of historical political factors (indeed, before GMT became the start zone, there were competing start zones in other countries). GMT as the start zone is mainly due to the predominance of the British Empire at the time that standardization was being set up.

In any case, while we traditionally indicate negative numbers for timezone offsets for zones to the West of Greenwich (i.e. Pacific Time is GMT-8), and positive number offsets for the East of Greenwich (i.e. Moscow Time is GMT+3), there is no hard and fast requirement for that. So, Pacific Time could easily be labeled as GMT+16. The existence of the International Date Line in changing the date as one moves across it means the standard form (minus to the West, plus to the East) is the most convenient method, though.

All of this is simply convention - that is, there has been some arbitrary decision made in the past, which has worked out well for all involved, so there is no real reason to change it. No other method would be less arbitrary (or be more "right"), so we stick with what has worked, even if there was no specific logical scientific reason to chose that implementation over others.

Answer 2

Time zones are typically ordered from east to west to reflect the Earth's rotation - starting from Greenwich Mean Time (GMT) as the reference point. This allows for easier coordination of time across the globe.