How to Set a 12-Hour or 24-Hour Clock in Windows 11 or 10

To set a 12-hour clock in Windows 11, open Settings, go to Time & language > Language & region, expand Regional format, click Change formats, and pick a Short time entry that shows AM or PM. The taskbar clock then reads 9:30 PM instead of 21:30.

To set 24-hour time (military time) instead, use the same menus and pick a Short time entry without AM or PM, such as 09:40, or choose HH:mm in Control Panel. The steps are in the 24-hour section below.

This changes only how the time is displayed. The actual time, your time zone, alarms and calendar events stay the same. The Region dialog steps follow Microsoft’s instructions for switching between a 12-hour and 24-hour clock and changing Windows regional settings.

Before You Start

• Version: These steps are for Windows 11 versions 25H2 and 26H2, the current releases on Microsoft’s Windows 11 release information page. They also match 24H2. The Region dialog method works the same on every version, and Windows 10 has its own section below.
• Two formats: Windows keeps a Short time (hours and minutes, used by the taskbar clock) and a Long time (adds seconds, used in places such as the calendar panel and some app dialogs). Change both so every part of Windows matches.
• Your account only: The time format is a per-user regional setting. You do not need administrator rights to change it, and other accounts on the same PC keep their own format.
• Work or school PCs: An organization can manage regional settings. If the options are unavailable, ask your IT administrator.

How to Change to 12-Hour Time in Settings

This is the shortest route. Settings gives you a list of ready-made formats, each shown as a sample time, so you never have to type a code.

1. Press Windows key + I to open Settings. You can also click Start and choose Settings.
2. Click Time & language in the left column, then click Language & region.
3. Under Region, click the Regional format row to expand it.
4. Click Change formats. On some builds the button is labeled Date & time format. A list of menus appears, including Short date, Long date, Short time and Long time.
5. Open the Short time menu and pick a sample that ends in AM or PM, such as 9:40 AM. An entry like 09:40 AM does the same thing but adds a leading zero to single-digit hours.
6. Open the Long time menu and pick the matching entry with AM or PM, such as 9:40:07 AM.
7. Close Settings. There is no Save button.

The taskbar clock should switch to 12-hour time as soon as you pick the new Short time. You do not need to restart.

If the time menus are under Date & time

Microsoft is moving the date and time formats from Language & region to Settings > Time & language > Date & time, where you can also change the AM and PM symbols. It announced the change in the Windows Insider Blog, so some PCs show the new layout and others still show the old one. If Regional format has no time menus on your PC, open Date & time and use the Short time and Long time menus there. The choices are the same.

How to Change to 12-Hour Time in Control Panel

The classic Region dialog is the method Microsoft documents for Windows 11, and it does not depend on which Settings layout you have. It also lets you type a custom format.

1. Press Windows key + R, type intl.cpl, and press Enter. The Region dialog opens. You can also open Control Panel and, under Clock and Region, click Change date, time, or number formats.
2. Stay on the Formats tab and find the Date and time formats section.
3. Open the Short time list and choose h:mm tt.
4. Open the Long time list and choose h:mm:ss tt.
5. Check the Examples area at the bottom of the dialog. Both time samples should now show AM or PM.
6. Click Apply, then OK.

Microsoft’s Outlook article writes the 12-hour formats as h:mm:tt and h:mm:ss:tt, with a colon before tt. Pick h:mm tt and h:mm:ss tt from the lists instead. A colon before tt would print a stray colon in front of AM or PM.

What the time codes mean

The Region dialog shows codes instead of sample times. Microsoft calls them format pictures and lists them in its hour, minute, and second format reference. Letter case matters: the hour letter must be lowercase for a 12-hour clock, and m, s and t are always lowercase.

Code	Meaning	Example
h	Hour on a 12-hour clock, no leading zero	9
hh	Hour on a 12-hour clock, with a leading zero	09
H	Hour on a 24-hour clock, no leading zero	21
HH	Hour on a 24-hour clock, with a leading zero	21 (09 in the morning)
mm	Minutes, with a leading zero	05
ss	Seconds, with a leading zero	07
tt	The full AM or PM marker	PM
t	Only the first letter of the marker	P

So h:mm tt gives 9:30 PM, hh:mm tt gives 09:30 PM, and HH:mm gives 21:30. A lowercase h without tt is a common mistake: the clock shows 9:30 for both morning and evening.

Type a custom format or change the AM and PM text

1. On the Formats tab of the Region dialog, click Additional settings. The Customize Format dialog opens.
2. Click the Time tab.
3. Type or select the format you want in Short time and Long time.
4. To change the marker text, edit the AM symbol and PM symbol boxes.
5. Click OK to close Customize Format, then OK again to close Region.

Warning: The Reset button in Customize Format restores the defaults for number, currency, time and date formats together. Do not click it if you have customized other formats and only want to undo a time change.

How to Confirm the Change and Undo It

• Taskbar: Look at the clock at the right end of the taskbar. It should show AM or PM.
• Calendar panel: Click the clock to open the calendar panel and check the time shown there.
• File Explorer: Open a folder in Details view. The Date modified column should list times with AM or PM.

To go back to 24-hour time, return to the same menus and pick the Short time and Long time entries without AM or PM, or choose HH:mm and HH:mm:ss in the Region dialog, as shown in the 24-hour section below. To go from 24-hour back to 12-hour, pick h:mm tt and h:mm:ss tt, the US defaults. Choosing your country again in the Regional format drop-down also resets every format to that region’s defaults.

What If Windows Still Shows 24-Hour Time?

• Check Short time first. The taskbar clock follows Short time. If you changed only Long time, the taskbar will not change.
• Check the code. In the Region dialog, the format needs a lowercase h and must include tt. An uppercase H always means 24-hour time.
• No AM/PM entry in the Settings list. Settings offers a fixed list of formats. If none of them shows AM or PM, use the Region dialog, click Additional settings, and type h:mm tt on the Time tab.
• Reopen apps. Apps that were open during the change may keep the old format until they restart. An Access database may need to be closed and reopened after changing regional settings. If the taskbar itself has not updated, sign out and sign back in.
• Check the app’s own setting. Some apps and many websites use their own time format and ignore the Windows one. Outlook is not one of them: its calendar uses your computer’s settings, so fix the format in Windows.
• The format changed back. Choosing a different country in the Regional format menu applies that region’s default date and time formats. Set Short time and Long time again afterward.
• The options are unavailable. On a work or school PC, regional settings may be managed by your organization. That is a question for your IT administrator.

If the clock shows the wrong hour, not just the wrong style, the format is not the cause. Check Set time automatically and your time zone under Settings > Time & language > Date & time. Here is how to change the date and time in Windows 11.

A correct clock and time zone also matter when you set reminders on Windows 11, because alerts follow the PC’s time.

How to Change to 24-Hour Time (Military Time)

Switching the other way uses the same menus. You pick formats without AM or PM, and the taskbar clock shows 21:30 instead of 9:30 PM.

Set 24-hour time in Settings

1. Open Settings > Time & language > Language & region, expand Regional format (click the row itself, not the drop-down menu inside it), and click Change formats. On newer builds, use Date & time instead, as described above.
2. Open the Short time menu and pick an example without AM or PM. With the English (United States) format you’ll see 9:40 and 09:40. The second one adds a leading zero to morning hours.
3. Open the Long time menu and pick the matching example that shows seconds and has no AM or PM.
4. Close Settings. Each choice applies as soon as you pick it.

Look at the taskbar clock. An afternoon time now reads 14:05 or similar, with no AM or PM.

Set 24-hour time in Control Panel

1. Press Windows key + R, type intl.cpl, and press Enter to open the Region dialog on the Formats tab.
2. Under Date and time formats, set Short time to HH:mm.
3. Set Long time to HH:mm:ss.
4. Click Apply, then OK.

Use an uppercase H for 24-hour time. If the format you want is not in the list, for example because your region uses a period between hours and minutes, click Additional settings, open the Time tab, and type it in the Short time and Long time boxes as described above.

Switch the whole regional format instead

If you also want your dates, numbers and currency to follow another country, change the regional format. Many regions, including the United Kingdom, default to a 24-hour clock.

1. Go to Settings > Time & language > Language & region.
2. In the Region section, open the drop-down menu next to Regional format and pick the region you want.
3. Close and reopen any open apps so they pick up the change. The taskbar updates right away.

This replaces any custom formats you set earlier with that region’s defaults. If you live in the US and only want the 24-hour clock, change only Short time and Long time, so your dates stay in month/day/year order.

If the clock still shows AM or PM

• No 24-hour option in the Short time list. The list only shows formats used by your current region. Use the Control Panel Additional settings steps and type HH:mm yourself.
• An app still shows AM and PM. Programs read the format when they start, so close the app and open it again. Signing out and back in catches anything that still lags.
• Outlook doesn’t change. Classic Outlook for Microsoft 365, Outlook 2024 and Outlook 2021 have no clock setting of their own and use the Windows format, according to Microsoft. Restart Outlook after you change Windows. Websites and web apps often use the settings in your online account instead.

Show Seconds in the Taskbar Clock

The taskbar clock does not show seconds by default, even after you pick a Long time format with seconds. To turn them on, open Settings > Time & language > Date & time, turn on Show time and date in the System tray, and select Show seconds in system tray clock (uses more power), as described in Microsoft’s time and date settings article. As the label says, this uses more power, which matters on a laptop running on battery. It works with both 12-hour and 24-hour formats, and you do not need a third-party clock app for it.

Set a 12-Hour or 24-Hour Clock on Windows 10

Microsoft ended Windows 10 support on October 14, 2025, so Windows 10 no longer gets free feature or security updates. The clock setting still works the same way.

Control Panel: Open Control Panel, then choose Change date, time, or number formats under Clock, Language, and Region. On the Formats tab, select h:mm tt for Short time and h:mm:ss tt for Long time. Check that the examples show AM or PM, then select Apply and OK. Microsoft’s clock-format instructions include this Windows 10 route.

Settings: Open Settings > Time & Language > Region, select Change data formats, and pick AM or PM entries for Short time and Long time. The taskbar clock updates right away.

24-hour time on Windows 10: Use the same Control Panel route and choose HH:mm for Short time and HH:mm:ss for Long time. The intl.cpl shortcut and the format codes work the same way as on Windows 11.

Frequently Asked Questions