2020-05-14 15:59:40.964 Error: dzVents: Error: (3.0.4) test timer script: /home/pi/domoticz/dzVents/runtime/Utils.lua:87: attempt to perform arithmetic on a nil value (local 'hours')
SwitchOff is executed and program stops execution right after.
The same 'at' conditions in
2020-05-14 15:59:40.964 Error: dzVents: Error: (3.0.4) test timer script: /home/pi/domoticz/dzVents/runtime/Utils.lua:87: attempt to perform arithmetic on a nil value (local 'hours')
at() does not use the relative timer rules. You can only use absolute times / days.
From the wiki..
.at(hh:mm[:ss][ on [ ddd|dddd ] ): Function.3.0.1 Activates the command at a certain time [ on a certain day]
device.switchOn().at('09:00') -- earliest moment it will be 09:00 hr.
device.switchOn().at('08:53:30 on fri') -- earliest moment it will be Friday at 08:53:30
device.switchOn().at('08:53:30 on sat, sun') -- earliest moment it will be Saturday or Sunday at 08:53:30 (whatever comes first)