Shutdown system at a specific time

I need to shutdown a server at a specific hour a few days from now. The command `shutdown <>`_ allows to specify the hour but not the day so that can't be used. It also allows to specify a number of minutes from "now" which implies computing that value. So the following can be used:

sudo shutdown -h +$(($(($(date -d 'yyyy-mm-dd hh:mm:ss' +"%s") - $(date +"%s"))) / 60))

I guess there is also the `at <>`_ command, though.