Here is how it works. The push button repeats itself in following sequence (must plug in). F 1 2 3 4 5 6 7 8 9 A d 1. 2. 3. 4. 5. 6. 7. 8. 9.
F: timer is off. 1 2 3 4 5 6 7 8 9: from dusk to dawn count down number of hours repeated every day. That's most useful to control outdoor lightings. A: from dusk to dawn count down number of hours which is randomly selected by this timer. Which is usually for indoor use to turn lights on and off for number of hours. The randomly selected hours is a security feature so that lights on (I believe the on time is within the range of 1 hour from dusk set by the timer) and off (it is randomly set, you can see the display blinking showing the selected countdown hours) shows no pattern to outsiders. d: just on from dusk and off at dawn. It is also used to control outside lights but just a little wasteful in my opinion. 1. 2. 3. 4. 5. 6. 7. 8. 9.: meaning count down number of hours starts from the time when the button is pushed so that you can have a countdown timer at any time.