Nahda

It's from the Night Shift Doctor Duty Procedure. It said that the shift lasts from 20.00 to 09.00, which is 13 hours. But the note said [Square]3 hours. So I assumed that [Square] = 1.

Then I put this into the light solution: Flicker 1 time, Long Flash 2 times, and Flicker 1 time. That gives the solution of: On-off (flicker) - turn on for 2 seconds, then off (Long Flash 1) - turn on for 2 seconds, then off (Long Flash 2), then on-off (flicker).

The switch also "resets" after eight presses, so that was another clue.