From the right edge of the screen, swipe left to display the charms menu.
Tap Change PC settings (located in the lower-right).
From the left pane, tap Time and language.
If not available, tap the Back icon (located in the upper-left) as necessary until "PC settings" appears in the upper-left.
From the Data and time section, tap the "Set time automatically" On/Off switch.
On (enabled; date+time settings are set via the Verizon Wireless network)
Off (disabled; date+time settings are set manually)
If configuring date+time settings manually, tap change then input the date and time as appropriate.
To change the appearance of the date and time, tap "Change date and time formats" (located under Formats at the bottom of the Date and time section) and select the desired view from the available dropdown menus.