Monday as first day of week for WeekArchiveView

How do I convin开发者_C百科ce WeekArchiveView that Monday is the first day of week?

Juding by this diff, it is achieved by adding week_format parameter to urls.py:

url(r'^items/(?P<year>\d{4})/week/(?P<week>\d{1,2})/$', ItemArchiveView.as_view(
    week_format='%W'
)),