use Time::Piece;

my $pubdate = "Thu, 11 Jun 2009 11:50:00 PDT";
my $t      = Time::Piece->strptime( "Thu, 11 Jun 2009 11:50:00 PDT", "%a, %d %b %Y %H:%M:%S %Z" );
my $offset = $t->tzoffset;

printf( "%s\n", $t );
printf( "%s\n", $t->tzoffset->seconds );