EX-816/824/1648 – Versions 1 and 2

From the Station 20 when idle:

Go off-hook and press [FEAT] + [5]
Enter the time [HH MM] using the 24 hour military clock
Go on-hook

EX-816/824/1648 – Version 3
EX-1232/2464 – Versions 1 and 2

From the Station 20 when idle:

Go off-hook and press [FEAT] + [8] + [1]
Enter the time [HH MM] using the 24 hour military clock
Go on-hook