Originally Posted By: hybrid8
They could probably adjust the time zone for their own schedules, but is the reason they don't simply one of population density? The East and West coasts have huge populations, but I don't know how they break down exactly as a percentage of the whole US.

I was curious, and found this from 2006. For the continental US only, the percentages are:
Eastern: 48.1% (141.6m)
Central: 29% (85.4m)
Mountain: 6.4% (18.7m)
Pacific: 16.6% (48.7m)
Total: 294.5m