Here is a breakdown of time zones and a map showing the various time zones in the United States.  

Eastern Time Central Time Mountain Time Pacific Time 
8:00 AM 7:00 AM 6:00 AM 5:00 AM
9:00 AM 8:00 AM 7:00 AM 6:00 AM
10:00 AM 9:00 AM 8:00 AM 7:00 AM
11:00 AM 10:00 AM 9:00 AM 8:00 AM
12:00 PM 11:00 AM 10:00 AM 9:00 AM
1:00 PM 12:00 PM 11:00 AM 10:00 AM
2:00 PM 1:00 PM 12:00 PM 11:00 AM
3:00 PM 2:00 PM 1:00 PM 12:00 PM
4:00 PM 3:00 PM 2:00 PM 1:00 PM
5:00 PM 4:00 PM 3:00 PM 2:00 PM
6:00 PM 5:00 PM 4:00 PM 3:00 PM
7:00 PM 6:00 PM 5:00 PM 4:00 PM
8:00 PM 7:00 PM 6:00 PM 5:00 PM

united-states-time-zone-map