Yes before or after by up to 30 mins
Dusk: Does -30 mean if the sun sets at 6:00 pm the devices are turned on/off at 5:30 pm? (+30 6:30 pm)?
Dawn: Does -30 mean if the sun rises at 6:00 am the devices are turned on/off at 5:30 am? (+30 6:30 am) ?
It is randomized with the randomizing window; plus or minus, UP TO thirty minutes from the set time, or from the calculated dusk/dawn times.
Not sure that I agree with this. When I set offset times, my lights turn on relative to sunset times. If I set the offset to -5, the light turns on 5 minutes before sunset...not dusk. Perhaps I am confused.
BTW, do not mix sunrise/sunset and dusk/dawn terminology. They are completely different. For instance, civil, nautical, and astronomical dusk times occur AFTER sunset!