- Call the extension number of the Auto Attendant
- When it answers, dial *789# (Two beep confirmation tone sounds)
- Dial *72
- Dial 1 to add an hour
- Dial 2 to subtract an hour (Two beep confirmation tone sounds)
- Dial *# to exit authorized caller mode
- Dial # to disconnect.
Note: On all ATL sets you must enter an additional # each time a
# appears in the programming command.