How to switch a world clock between 12 and 24 hours

Do you prefer seeing 2:30 PM or 14:30? A world clock can show the same moment in either format, but the setting is easy to miss when you are checking several cities at once.

Use the World Clock to choose the format you find easiest to read. If its display does not change, check whether the clock has its own format option or follows your device's time settings.

Switch the world clock format

1. Open the World Clock.
2. Find the time format control in the clock's settings or display options. Choose the 12-hour format to show AM and PM, or choose the 24-hour format to show times from 00:00 to 23:59.
3. Check a city whose local time is after noon. In 12-hour format, the time should have a PM marker. In 24-hour format, an afternoon time should be 13:00 or later.
4. Check the time near midnight too. Midnight may appear as 12:00 AM in 12-hour format or 00:00 in 24-hour format.

Changing the display format does not change a city's time zone or the time itself. It only changes how the hour is written.

What the two formats look like

12-hour time shows AM or PM

The 12-hour clock counts from 1 to 12 twice each day. AM covers midnight up to just before noon, and PM covers noon up to just before midnight. For example, 3:00 PM is in the afternoon, while 3:00 AM is early morning. Check that the AM or PM marker is visible, especially when comparing cities across different time zones.

24-hour time counts from 00 to 23

The 24-hour clock counts continuously through the day. 00:00 is midnight, 12:00 is noon, and 18:00 is 6:00 PM. This format removes the need for AM and PM, which can make schedules easier to compare at a glance.

The hour changes but the city time does not

If 4:00 PM becomes 16:00, the format changed as expected. If the actual time seems different by several hours, check the city or time zone selection instead. The 12-hour and 24-hour formats represent the same instant.

If the format will not change

1. Check for a separate clock setting. Look in the World Clock's display or settings options for a 12-hour or 24-hour choice. If you find one, use it first because an individual tool can have a setting separate from your computer.
2. Refresh the page. If you changed a device setting, reload the World Clock so the page can read the current preference. Check the time again after it loads.
3. Check the Windows time format. On Windows 11, open Settings › Time & language › Language & region and review the regional format options. If the World Clock follows the system format, choose a regional format that uses the time style you want.
4. Check the Mac time format. Open System Settings › General › Date & Time and review the 24-Hour Time option. Turn it on for 24-hour time or off for 12-hour time, then reload the clock page.
5. Check your phone's time setting. On an iPhone, open Settings › General › Date & Time and change 24-Hour Time. On Android, look under Settings › System › Date & time for Use 24-hour format. Menu names can vary by phone maker.
6. Try a private or refreshed browser tab. A page may keep its earlier display until it reloads. Reopen the tool in a fresh tab and check the format selector again.

System settings may affect other clocks and apps, not just the World Clock. If you only want this one clock to look different, use its own format option when available.

Why city times can look confusing

The format is separate from the time zone. For example, if one city shows 7:00 PM and another shows 01:00, the second city is displaying 24-hour time and may also be on a different local date. Compare both the hour format and the date when planning a call across time zones.

For a quick conversion, add 12 to a PM hour other than 12: for example, 7:00 PM becomes 19:00. For a 24-hour time greater than 12, subtract 12 and use PM: 19:00 becomes 7:00 PM.