+=item _subtract_months: subtracts the number of months from a given unix date stamp
+
+=cut
+
+sub _subtract_months {
+ my($self, $number_of_months, $time) = @_;
+ my ($sec,$min,$hour,$mday,$mon,$year) = (localtime($time) )[0,1,2,3,4,5];
+ $mon -= $number_of_months;
+ if ( $mon < 0 ) { $mon+=12; $year--; }
+ timelocal($sec,$min,$hour,$mday,$mon,$year);
+}
+