HOW TO CHANGE THE SYSTEM DATE AND TIME
With your phone idle and the handset on-hook, complete the following steps
Press [TRANSFER] and Dial 200
Enter the password 1234
Press 1 to Enable
Press Speaker and dial 505
Enter the day of the week (Monday is 1, Tuesday is 2, Wednesday is 3, etc.)
Enter 2 digits for the month (March would be 03)
Enter 2 digits for the date
Enter 2 digits for the year
Enter the hour in 24 hour format (9 am is 09, 3 pm is 15)
Enter the minutes
Press [TRANSFER] to save and exit
How to change the system date and time.