Panel - Clock - Setting time format

Tip
Setting the time format for the clock in KDE4 is a bit different than KDE3. If you right-click on the clock on the panel, you get the options of Manage date and time and Digital Clock Settings, as well as the option to copy a variety of time-related information to the clipboard. None of these options allow you to change the time format, however.

To change the time format, you need to open KDE's configuration center (the icon for it is a screwdriver and wrench in an "X"). From there, click Regional & Language. From there, click the Time & Dates tab. The Time Format controls the format of the digital clock in the panel. By default, it should show PH:MM:SS AMPM (this may vary depending on your country/language settings).

If you want 24-hour format, click the drop-down box and select HH:MM:SS (you can also type this manually if you want). If you want 12-hour AM/PM format without a preceding zero for single-digit hours, select or type pH:MM:SS AMPM. The lower-case "p" indicates to drop the zero before single-digit hours, but show the 1 when the clock reaches a two-digit hour.

Examples:
 * PH:MM:SS - 01:45
 * pH:MM:SS AMPM - 1:45 pm
 * HH:MM:SS - 13:45