my @bits = split ' ', localtime( time() - ( 45 * 24 * 60 * 60 ) );;
my $n = 1; 
my %months = map{$_, $n++} qw[Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec];;

my $targetDate = join '-', $bits[ 4 ], $months{ $bits[ 1 ] }, $bits[2];;
print $targetDate;;

2007-11-28

##</code><code>##

open OLDDB, '<', $dbname or die ...;
open NEWDB, '>', $tempfile or die ...;
open ARCHIVE, '>>', $archive or die ...;

print ARCHIVE while defined( $_ = <OLDDB> ) 
                and substr( $_, -17, 10 ) lt $targetDate;

print NEWDB; ## Output first 'failing' record to newdb
print NEWDB while <OLDDB>;

close for OLDDB, NEWDB, ARCHIVE;
unlink $dbname;
rename $tempfile, $dbname;