It would be handy to have "Twilight" as a job start up condition, possibly with an offset. For example, "Start the job at Twilight +15m", etc.

This would also help prevent jobs from failing to start when the time is set prior to local astronomical twilight when the job constraint "twilight" is set. A condition where you might want this is if the job runs all night and you want it to stop at astronomical dawn.

It seems like ASAP does this. This was not immediately clear to me. I took it as "start immediately", which would then fail due to the job constraints.