12-hour and 24-hour time explained
Make sense of am, pm, midnight, and the 24-hour clock, with simple examples you can use immediately.
Two ways to label the same hour
The 12-hour clock divides the day into am and pm. The 24-hour clock numbers hours from 00 through 23, so each clock reading has a unique hour within the day.
Both formats represent the same time. Switching between them changes the display, not the selected instant or time zone. Use the 12 hr / 24 hr buttons in the converter to choose your preferred view.
Convert am and pm to 24-hour time
For 1 am through 11 am, keep the hour and add a leading zero if needed: 7:30 am becomes 07:30. Midnight, 12 am, becomes 00:00.
For 1 pm through 11 pm, add 12 to the hour: 2:45 pm becomes 14:45, and 11:10 pm becomes 23:10. Noon, 12 pm, stays 12:00. The minutes never change.
The midnight trap
12 am means midnight at the start of a date, while 12 pm means noon. If an event is close to midnight, write out the date and use 00:00 or the word “midnight” to reduce confusion.
When a time zone conversion crosses midnight, the destination may have a different date. The converter shows a +1 day or −1 day indicator relative to the first city.
Use the format your audience understands
The 24-hour format is useful for travel schedules and international teams because it avoids missing am or pm. The 12-hour format may feel more natural for casual plans in places where it is common.
A clock format is not a time zone. “14:00” still needs a location or UTC offset, and a date, to identify the exact moment.
Put it into practice.
Compare your cities, choose a date, and find a moment that works.
Open the time converter →Sources & further reading
Time zone rules and identifiers: IANA Time Zone Database. Time standards and clock terminology: NIST Time of Day FAQs. See how our converter calculates time for implementation details and limitations.