Found this on the internet. Hope it helps.

WIN... including 24D, 36D, 36DX, and 100D

Note: The time can only be set from an assigned display phone or Station 10. On a WIN 100D, time is to be set from the Receptionist phone. Performing this operation will adjust the time setting on all display phones.

Press FEAT button
Dial 32
Dial 4 Digit Hour
Dial * for AM or Dial # for PM
Press FEAT button
Press HF button


Retired phone dude