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Unfortunately you'll have to configure both days with two seperate times.
For example if you want to start in Sunday 22:00 (PM) till Monday morning 3:00 (AM) you'll have to configure two times triggers:
1. Sunday, from 22:00 to 23:59.
2. Monday, from 00:00(AM) to 3:00.
There is another way if you want to use the RTC and compare function. for example:
Create a register for each timer section (HH,MM)
1.Compare the HH to current RTC hours.
2. Compare the MM to current RTC minutes.
And if both are valid it will execute the system.
If you have any more question please send us an email to firstname.lastname@example.org