Cache preload always at same time of day?

Hi, the time between cache preload is always calculated from the END of a process.
So if I set 1440 minutes as time between processes and the process lasts 1 hour, preload will start 1 hour later day by day. The problem is that the process doesn’t always take the same amount of time so it’s not possible to start the process maybe at 1 o’clock each night.

Is there a way to change that?

Thank you, regards, Achim