How do i change the time and date on my hp officejet 6310 printer

First of all, congrats, you are using one of the best printer on the market.
For HP Officejet 6310 :-
To set the date and time
1. Press Setup.
2. Press 6, and then press 3.
This selects Tools and then selects Date and Time.
3. Enter the month, day, and year by pressing the appropriate numbers on the
keypad. Depending on your country/region setting, you might enter the date in a
different order.
4. Enter the hours and minutes.
5. If your time is displayed in the 12-hour format, press 1 for AM, or 2 for PM.
The new date and time settings appear on the display.
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And, you can also download it's User Manual from :-
http://h10032.www1.hp.com/ctg/Manual/c00633922.pdf

To change date and time you have to go to the menu of the printer where u will find the setting for that..