Samsung

The time change can be made from any display telephone on the system.  

Enter the codes shown below with the handsets down & always input the entire entry for the date and time entry including the minutes on the telephone keypad even though you may only be changing the hour.

PROSTAR 816 

Enter programming mode by entering #04 followed by passcode followed by 1#.  The telephone will show the date and time again.  Enter #55 and the display will show YY MM DD W HH MM.   Enter the year for YY, the month for MM, the day for DD, the day of the week for W (Monday =1, Sunday=7), the hour in military time for HH, and the minutes for MM. Then enter #.

PROSTAR 816 PLUS

Enter #06 followed by passcode followed by 1# to enter programming mode and then follow step 2 for the Prostar 816.

PROSTAR 1224 AND 56EX
 

Enter programming mode by entering #20 followed by passcode. Press the MUTE key followed by #. The phone will show the date and time again.

Enter #70 and the display will show YY MM/DD W HH:MM.  Enter the year for YY, the month for MM, the day for DD, the day of the week for W (Monday=1, Saturday=6), the hour in military time for HH, and the minutes for MM. Then enter #.

SAMSUNG DCS  

Enter programming mode by entering TRSF followed by 200. Enter passcode and then press by volume up arrow on the phone to enable programming. Enter TRSF to return to the date and time.

Enter TRSF followed by 505 and the display will show WMMDDYY:HHMM.   Enter the day of the week for W (Monday=1, Saturday=6), the month for MM, the day for DD, the year for YY, the hour in military time for HH, and the minutes for MM. Then enter TRSF.