To access the Time and date settings, follow these steps:
From the Settings menu, select General, then touch Date & time
Verify the following:
It is recommended to select Use network-provided time. This option is active by default.
If you would like to change the time format from 12-Hour:
Use the following additional steps
Deselect Use locale default
Select Use 24-hour format
The date format shown on the Time screen is MM/DD/YYYY. This format cannot be changed.