Most of the PST timezone games and players I have participated with have been listed under EST. It's sort of become the standard used for games in North America unless someone new to roll20 is listing a game. It's not uncommon for instance to find games that start at 20:00 EST, which is 5PM PST. That is pretty late for many people actually in the EST timezone on a work/school night. Central is also seen sometimes, but nowhere near the frequency of EST. EST is sort of just the universal used.