The setDate( command sets the date of the clock on the TI-84+/SE calculators. It takes three arguments: the year, the month, and the day. All three of these must be integers; in particular, year must be four digits, and month and day can be one or two digits. They represent the associated value that goes with a respective date. For example, this would set the date to January 1, 2008:
Once you have set the date, you can display it in three different formats on the mode screen using the setDtFmt( command: Month/Day/Year, Day/Month/Year, or Year/Month/Day. Of course, the date will only show up if the clock is on; if you need to turn the clock on, use the ClockOn command or select 'TURN CLOCK ON' , displayed in place of the clock on the mode screen.