I played with two rsync patches on some other distros last years. It appears these are not installed on Univention by default.
When this option is used rsync will stop after T minutes and exit. I think this option is useful when rsyncing a large amount of data during the night (non-busy hours), and then stopping when it is time for people to start using the network, during the day (busy hours).
This option allows you to specify at what time to stop rsync.
I see some useful value in these options. Are these options something you may consider adding by default going forward?