The 24-Hour Clock, also known as "Military Time"
Often referred to as "military" time, the 24-hour clock is routinely used for a number of applications. This system is formally referred as Universal Military Time [UMT].
Converting to time from traditional "AM" and "PM" time to a 24-hour clock is done by dividing the day into 24-hours, starting at midnight (00:00). Time counts upward, continuing to increase after noon so that references to "AM" or "PM" are discarded, and afternoon/evening are indicated by any number higher than 1200 (i.e., 1:00 p.m. = 1300; 2:00 p.m. = 14:00; see chart below).
A simple rule of thumb to convert time to a 24-hour clock to add 12 to P.M. times (or subtract 12 to convert from the 24-clock, e.g., 2130 - 1200 = 9:30 PM)
| - AM - | - PM - | ||||
| 24-Hour Clock | Traditional | 24-Hour Clock | Traditional | ||
| 0001 Hrs | = | 12:01 AM | 1201 Hrs | = | 12:01 PM |
| 0100 Hrs | = | 1:00 AM | 1300 Hrs | = | 1:00 PM |
| 0200 Hrs | = | 2:00 AM | 1400 Hrs | = | 2:00 PM |
| 0300 Hrs | = | 3:00 AM | 1500 Hrs | = | 3:00 PM |
| 0400 Hrs | = | 4:00 AM | 1600 Hrs | = | 4:00 PM |
| 0500 Hrs | = | 5:00 AM | 1700 Hrs | = | 5:00 PM |
| 0600 Hrs | = | 6:00 AM | 1800 Hrs | = | 6:00 PM |
| 0700 Hrs | = | 7:00 AM | 1900 Hrs | = | 7:00 PM |
| 0800 Hrs | = | 8:00 AM | 2000 Hrs | = | 8:00 PM |
| 0900 Hrs | = | 9:00 AM | 2100 Hrs | = | 9:00 PM |
| 1000 Hrs | = | 10:00 AM | 2200 Hrs | = | 10:00 PM |
| 1100 Hrs | = | 11:00 AM | 2300 Hrs | = | 11:00 PM |
| 1200 Hrs | = | 12 Noon | 0000 Hrs | = | 12 Midnight |
