Sorry, you want this to not run at the weekend? At the moment, with the condition that the workday sensor is 'off', it will only run at the weekend. The automation will check that the conditions are true before proceeding, and binary_sensor.workday_sensor will only be 'off' on Saturday and Sunday. On weekdays, that condition will not be met and the action will not happen.
Also, I spot a potential race condition. If, at midnight, this automation is triggered and processed before the binary_sensor.workday state is updated, you could potentially have it not trigger first thing on a Saturday, but trigger first thing on a Monday.
Unless it’s super-critical that it occurs exactly at midnight, it may be safer to trigger at 00:01.
The hint with the race condition was useful, i had an automation triggered at 00:00:00 with the condition workday on. But workday was updated at 00:00:28…
Is it safe to use 00:01:00? Is the sensor updated every minute?
Can the update cycle be adapted?