Hi Cédric,

tested your patch now:
It solved 3 our of 4 cases for me.
When being on Nov 999, the next link for the month is shown
and leads to exceptions.OverflowError'>: date value out of range
in line 
        for week in calendar.monthcalendar(display.year, display.month):

If you happen to do a new patch, could you add a CHANGES.txt
entry as well? :)

Thanks,
Bernhard