The 24-hour time system is used for search operations, as it dispenses with the use of a.m. or p.m. and thus reduces the risk of error. It is always used in radio communication.

  • The time is written as four figures.
  • The first two figures of the group represent the hours past the previous midnight from 00 to 23 inclusive.
  • The second two figures of the group represent the number of minutes past the hour from 00 to 59 inclusive.
  • The group is always followed by the word “hours”.
Time24-Hour representationSpoken form
12 midnight0000 hourszero hundred hours
12:07 am0007 hourstriple zero seven hours
1:00 am0100 hourszero one hundred hours
10:00 am1000 hoursten hundred hours
5:14 pm1714 hoursseventeen fourteen hours
11:59 pm2359 hourstwenty-three fifty-nine hours