Thanks for your reply, but my problem is not solved
I have a licensed version 4.2.0.21. Scan only works with the method ip range scaning because computers are not in the microsoft domain but in samba domain.
I set the ip range scanning in two rows that contain the same address range and assign each a different time. it does not work
ip range
192.168.1.1 - 192.168.1.254 time: 23:00
192.168.1.2 - 192.168.1.254 time: 07:00