For the shifter it feels stupid to wait for the video being generated.
I think it would be good to use 'End of day time' for the start of the video and 'End of astron. twilight' for the end. This starts the video early enough, to still have some pre-operation time but stops only 10minutes after the scheduled 'begin of shutdown', that should be exacrly the time of the last single pe run in parking Position.
We can either use astropy and calculate the times ourselves, or use the smart-fact-crawler and read the times from our own page. Both should be just fine.