Dear Erel,
Ok, understood.
I have read in the blogs about an Alarm Clock example that comes with the SDK, but I didn't checked it.
I have tried with the combination of all the ways found in the B4A support:
StartServiceAtExact
StartServiceAt
Service.StartForeground(..)
#StartCommandReturnValue: android.app.Service.START_STICKY
Adding dummy timers firing every second
Adding timers that should fire at the same time , before or after the Service Star
So far , I found the following behavior:
1 - the delay firing is random, spanning from 1 second to 10+ minutes, when happens, the delay lasts even after you wake up the device manually (*)
2 - the delay firing increases with the lapse, ie, when you schedule to fire every 5 secs it fails less times and for less time delay than when the lapse is 20 secs
(*) this is odd, the log doesn't show that the service started, but shows entries for traces I added, In this scenario, even the timers doesn't fire
I will try scheduling a fixed short lapse, testing from 1 to 10 seconds StartServiceAt lapse, because it seems the current OS' strategy let's alone tasks firing frequently.....