Subtract 1200 from from the military notation if you are dealing with a military time of 1300 hours or greater. If it is less than 1300 hours, skip this step.
For example: 2300 -1200 = 1100
The only exception to this rule is numbers that begin with "00". In this case, add 12. 0030 hours is 12:30.
Place a colon between the second and third number in the military notation. For example, 1130 hours becomes 11:30. Omit the first 0 if the military time begins with one 0. For example, 0300 hours would not be expressed as 03:00, but as 3:00.
Place an a.m. after all military times of 1159 and below, as well as 2400. For example, 0945 is 9:45 a.m. Place a p.m. after all military times between 1200 and 2359.