I live in the Central Time Zone. When I attach a file in my Google Site, it shows Pacific Time for the Attachment Time. Is there anyway to have it show Central Time?
This is not a per-site setting, but a user setting (as a user of Sites). Follow these instructions to change your time-zone preference:
From this point forward, all times within Google Sites should be presented in Central Time. Of course, other people might decide to look at your Site using a different time-zone, but that's, of course, their choice.