Enhance backgroundjob timings

[rullzer]

This adds the AtJob backgroundjob. A background job that will run once a day after, but as close to the specified time as possible.

Example usages:

• Run share expiration as close to midnight as possible
• Run suspiciouslogin training at 03:00 when the system is likely to have low usage

There is also teh dailyJob which is just a prefilled instance to run at midnight.

TODO;

• Tests

[rullzer]

@ChristophWurst @nickvergessen @blizzz @juliushaertl @skjnldsv

feedback is welcome ;)

[nickvergessen]

My main concern with stuff like this is, we can not know whethere an instance has such working times, and when they are. 🤔

[rullzer]

Well sure. But that is the same with jobs right now.

My concern is that with some jobs that run daily we have to make sure they run early that day. Otherwise the notification might not make sense anymore

[ChristophWurst]

My concern is that with some jobs that run daily we have to make sure they run early that day. Otherwise the notification might not make sense anymore

Which jobs are those?

[rullzer]

My concern is that with some jobs that run daily we have to make sure they run early that day. Otherwise the notification might not make sense anymore

Which jobs are those?

• Share expiration jobs ideally
• Possible new jobs like in Enh/share expiration notification #17727 where we want to send a notification a day in advance. It is of little use if that gets send at 23:00 on day A and the share expires at 00:00 on day A+1

[ChristophWurst]

Yes, but the argument remains that we don't know the working hours of every instance. Instances are also used for different time zones and then "night", "day" and "early that day" are ambiguous time frames.

[rullzer]

@ChristophWurst not really. If your machine operates in timezone A. then allyour share expiration dates are in that timezone. So if you want to clean them up

In any case. @nickvergessen had a better idea so lets close this for now.