Tvheadend

Hi there,
yesterday i found the wiki entry for the ACPI Wakeup script and just tried it on my unRaid Server https://tvheadend.org/projects/tvheadend/wiki/Wakeup
Worked instantly without any problems. But there is one thing that bugs me, it does not use the prerecording time i have set in the TVHeadend Config. The reason why is simple, it only parses the start time in the dvr/log files, which only shows the real start time of the show.

The quick and dirty solution is to set an appropiate safty-margin, which works when you only have one recording profile.
Has anybody already solved this problem in a correct way?

I know there are far more sophisticated scripts here in the forum which also handle shutdown etc. But that are mostly functions i don't need, because these are handled by different plugins in my server.