How to change Outlook calendar to military time (24-hour clock)?

Author Kelly Last modified 2025-04-08

When showing a calendar in Day / Work Week / Schedule View in Outlook, the time labels are shown as 12-hour clock, such as 10AM, 1PM, etc. Here, this article will show you the way to change time format, and show the time labels as military time (or 24-hour clock) easily in Outlook calendar.

Change Outlook calendar to military time (24-hour clock)

the screenshot of changing Outlook calendar to military time (24-hour clock)

Change Outlook calendar to military time (24-hour clock)

This method will guide you to change the time format in Outlook calendar and show all time labels as military time or 24-hour clock. Please do as follows:

1. Open the "Control Panel" with one of below ways:

A. In Windows 10, please click the Search icon at task bar, type control panel into the search box, and then select the "Control Panel" in search results. See right screenshot:

B. In Windows 8, press "Win" + "S" keys to activate the "Search" pane, type Control Panel into the "Search" box, and then click "Control Panel" in the search results.

C. In Windows 7, please click "Start" > "Control Panel".

the step 1 of changing Outlook calendar to military time (24-hour clock)

2. In the opening Control Panel, type Region into the search box right to the folder address box, and then click "Region" (or "Region and Language") in the search results. See screenshot:

the step 2 of changing Outlook calendar to military time (24-hour clock)

3. Now the Region dialog box comes out. Under the "Formats" tab, please (1) select "HH:mm" from "Short time" drop down list, (2) select "HH:mm:ss" from "Long time" drop down list, and (3) click the "OK" button. See screenshot:

the step 3 of changing Outlook calendar to military time (24-hour clock)

Note: For changing to custom time format in Outlook calendar, please (1) click the "Additional settings" button in the Region dialog box; (2) in the Customize Format dialog box, enable "Time" tab, (3) type time format codes into both "Short time" and "Long time" boxes, and (4) click "OK" buttons to save the changes. See screenshot:

the step 4 of changing Outlook calendar to military time (24-hour clock)

After configuring the time format in the Control Panel and returning to Outlook calendar, you will see the time labels are changed to military time (24-hour clock) as below screenshot shown.

the step 5 of changing Outlook calendar to military time (24-hour clock)

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