UTC
EDT/AST
CDT/EST
MDT/CST
PDT/MST
PST
0000*
2000
1900
1800
1700
1600
0100
2100
2000
1900
1800
1700
0200
2200
2100
2000
1900
1800
0300
2300
2200
2100
2000
1900
0400
0000*
2300
2200
2100
2000
0500
0100
0000*
2300
2200
2100
0600
0200
0100
0000*
2300
2200
0700
0300
0200
0100
0000*
2300
0800
0400
0300
0200
0100
0000*
0900
0500
0400
0300
0200
0100
1000
0600
0500
0400
0300
0200
1100
0700
0600
0500
0400
0300
1200
0800
0700
0600
0500
0400
1300
0900
0800
0700
0600
0500
1400
1000
0900
0800
0700
0600
1500
1100
1000
0900
0800
0700
1600
1200
1100
1000
0900
0800
1700
1300
1200
1100
1000
0900
1800
1400
1300
1200
1100
1000
1900
1500
1400
1300
1200
1100
2000
1600
1500
1400
1300
1200
2100
1700
1600
1500
1400
1300
2200
1800
1700
1600
1500
1400
2300
1900
1800
1700
1600
1500
2400*
2000
1900
1800
1700
1600

Universal Coordinated Time (UTC) is the time at the zero or reference meridian.
Time changes one hour with every change of 15 degrees in longitude.
The five time zones in the U.S. proper and Canada roughly follow these lines.

0000* and 2400 are interchangeable.
(2400 is associated with the date of the day ending, 0000 with the day just starting.)

Courtesy of the ARRL - The American Radio Relay League, Inc