With the default settings Windows 10 shows the 24-hour clock format on the taskbar and as well as the lock screen. Although there is nothing wrong with it but some users find it difficult to read time from there and are more comfortable with the more common and easy 12-hour format clock.
If you use Windows 10 and prefer the 12-hour clock over the 24-hour format or vice-versa following are the instructions you need to follow.
Note that this will not have any effect on the lock screen clock as it will continue to show the time in 24-hoour format, unfortunately currently there is no method to change that.
Method 1 of 3
Change time format from 24-hour to 12-hour via Settings
Step 1: Click on the date and clock in the taskbar and then click Date and time settings to open Time and Language section in Settings app.
Step 2: Under Formats click on the link labelled Change date and time formats.
Step 3: At last under the Short time section, select hh:mm tt to see 12-hour time format instead of the default 24 hour.
Also, under Long time section, select hh:mm:ss tt.
NOTE: Instead of hh:mm tt you can also select h:mm tt. When you select h:mm tt instead of hh:mm tt, Windows displays 04:29 as 4:29 (removes the initial zero).
Method 2 of 3
Change clock format from 24 hour to 12 hour via Control Panel
Step 1: Open Control Panel.
Step 2: Look for Language.
Step 3: On the left hand side click on Change date, time, or number formats link.
Step 4: Under Formats tab, under Date and time formats section, select hh:mm tt from the drop-down box next to Short time.
Select hh:mm:ss tt from the drop down box next to Long time.
Click Apply button.
Method 3 of 3
Customize AM and PM symbols
You can customize AM and PM symbols to and it’s kind of fun as you can edit it to show your name or any other word you like. To do so:
Step 1: Follow the instructions mentioned in Step 1, Step 2 and Step 3 of Method 2.
Step 2: Click Additional settings.
Step 3: Switch time tab by clicking on the same.
Step 4: In the field next to AM Symbol, enter what you want to use instead of the default symbol. Likewise, enter something in the field next to PM Symbol. Click Apply button.