@var{mark} which specifies how to mark the date in the calendar display.
If one of these functions decides that it applies to a certain date,
it returns a value that contains @var{mark}, as described above.
@var{mark} which specifies how to mark the date in the calendar display.
If one of these functions decides that it applies to a certain date,
it returns a value that contains @var{mark}, as described above.