[Koha] Do not set notices when library is closed

[zefanja]

Hi Katrin,

> overdue notices can be send out on opening days only using the
> |OverdueNoticeCalendar system preference. It works similar to the
> finescalendar system preference and allows to time overdue notices and
> adding of fines to happen on the same days, which was a demand for a lot
> of our libraries. For predue notices it's currently not possible to send
> them only on days the library is open.

Thank you for the hint. That helps a lot. Overdue notices are more
important to us. Predue notices would be nice, too, but not that urgent.

Regards,
Stephan