The setTime( command sets the time of the clock on the TI-84+/SE calculators. It takes three arguments: the hour, the minute, and the second. The hour must be in 24 hour format -- where 13 is equal to 1 P.M. -- and the minute and second need to be a valid number within the appropriate range (1-60). For example, this would set the time to 12:30:30:
Once you have set the time, you can display it in two different formats on the mode screen using the SetTmFmt( command: 12 (12 hour) or 24 (24 hour). Of course, the time will only show up if the clock is on; if you need to turn the clock on, use the ClockOn command, or scroll down to the 'TURN CLOCK ON' message that is displayed in place of the clock on the mode screen and press ENTER twice.