Setting the time format Click to see a larger image

When you first set up your Mac, it determines where you are located and sets the appropriate date, time, number and currency formats for that region. For time formatting, some countries use a 12 hour clock with AM/PM and some use a 24 clock. You can change between the 12 and 24 clocks without changing the formatting for dates, numbers and times. The most obvious effect of changing between 12 and 24 hour clocks is the Event times in iCal.

To change time formats:

1. Open System Preferences from the Dock or the Apple Menu.
2. Choose Language & Text preferences.
3. Choose the Formats tab.
4. In the middle of the window is the current date format. Click the Customize… button to the right.

There are four time formats used on the Mac: Short, Medium, Long and Full. You must change each of these.

1. The first light blue "bubble" in each format is the hour format. Click the white down arrow on each one and choose 0-23.
2. Click on the PM bubble for each line and hit the Delete key. Note: If you are changing from a 24 clock to a 12 hour clock, drag the PM bubble from the Time Elements box up to each field.
3. Click the OK button.

The region for your computer will now be set to Custom. If at any time you want to change the times back to your region's standard format, simply select your region from that dropdown box.

If iCal was open before you started the format change, quit it and re-open to see the new time formats for Events.

As mentioned earlier, the most obvious effect of changing clock formats is in iCal because most Events have starting and ending times. However, the clock format change is made system wide. This means that the format will change in any application that shows time, such as the Finder, iPhoto (photo capture date and time) etc. Even the Menu Bar clock will change format, but not until you log out of your account and back in.

Related Items: System Preferences | iCal