And after the homework, try this:
use DateTime;
use DateTime::Format::Strptime;
my @start_date = qw(01-06-2007 01-08-2006 01-06-2006 01-07-2007 06-01-
+2007);
my $Strptime = new DateTime::Format::Strptime( pattern => '%d-%m-%Y' )
+;
my @start_datetimes;
foreach my $datetime ( @start_date ) {
push @start_datetimes, $Strptime->parse_datetime( $datetime );
print $start_datetimes[-1]->ymd('-');
}
print "-"x10;
my @sort_datetimes =
map { $_->[0] }
sort { $a->[1] <=> $b->[1] }
map { [ $_, $_->epoch ] }
@start_datetimes;
print $_->ymd('-') foreach @sort_datetimes;
__OUTPUT__
2007-06-01
2006-08-01
2006-06-01
2007-07-01
2007-01-06
----------
2006-06-01
2006-08-01
2007-01-06
2007-06-01
2007-07-01
Note: Teachers don't likes modules :-)