Converting Between AM/PM and 24 Hour Clock: making the conversion

Converting Between AM/PM and 24 Hour Clock making the conversion

Converting from AM/PM to 24 hour clock:

between 12:00 AM and 12:59 AM, subtract 12 hours:
12:59 AM --> 0059
between 1:00 AM and 12:59 PM, a straight conversion:
10:00 AM --> 1000
between 1:00 PM and 11:59 PM, add 12 hours:
10:59 PM --> 2259

Converting from 24 hour clock to AM/PM:

between 0000 and 0059, add 12 hours:
0059 --> 12:59 AM
between 0100 and 1159, straight conversion to AM:
0100 --> 1:00 AM
between 1200 and 1259, straight conversion to PM:
1259 --> 12:59 PM
between 1300 and 2359, subtract 12 hours:
1559 --> 3:59 PM

definition

Terms for using data resources. CD-ROM available.
Credits and Acknowledgments for WW2010.
Department of Atmospheric Sciences (DAS) at
the University of Illinois at Urbana-Champaign.

am/pm to utc