Clock Format Converter

Time can be displayed in 12-hour or 24-hour format.

12-hour to 24-hour conversion:

• 12:00 AM (midnight) = 00:00
• 12:30 AM = 00:30
• 1:00 AM = 01:00
• 12:00 PM (noon) = 12:00
• 1:00 PM = 13:00
• 6:00 PM = 18:00
• 11:59 PM = 23:59

Quick rule:

• AM hours (except 12 AM): same number
• 12 AM = 00 (midnight)
• PM hours: add 12 (1 PM = 13, 2 PM = 14, etc.)
• 12 PM stays 12 (noon)

Military time is the same as 24-hour format but spoken differently:

• 00:00 = “zero hundred hours”
• 08:30 = “oh-eight-thirty hours”
• 13:00 = “thirteen hundred hours”
• 23:45 = “twenty-three forty-five hours”

Most of the world uses 24-hour time. The 12-hour format is mainly used in the United States, Canada, Australia, and a few other countries.

Almost everyone has the 24-hour clock down except for the two values that actually trip people: midnight and noon. The mistake is assuming 12 PM is midnight. It isn’t. Noon is 12:00, and midnight is 00:00, and that single swap causes most of the confusion around appointments and alarms. Once you have memorized those two anchors, the rest is just “add 12 to afternoon hours.”

The reason hospitals, airlines, and the military all use 24-hour time is that it removes the ambiguity entirely. There is no way to misread 14:00 as anything but 2 PM, whereas “a 12:00 flight” genuinely could be either end of the day. One quirky edge case: midnight at the end of a day is sometimes written 24:00 rather than 00:00 of the following day, which is why a train timetable might list a service at 24:00. They mean the same instant; 00:00 just resets the date.