@property<EOL><INDENT>def lastOfferedMonth(self):<DEDENT>
lastOfferedSeries = self.event_set.order_by('<STR_LIT>').first()<EOL>return (lastOfferedSeries.year,lastOfferedSeries.month)<EOL>
Sometimes a Series is associated with a month other than the one
in which the first class begins, so this returns a (year,month) tuple
that can be used in admin instead.