my $dt1 = DateTime->from_epoch( epoch=>1403785930,
    time_zone=>'Europe/London' );
my $dt2 = DateTime->new( year=>2014, month=>6, day=>26, hour=>14,
    minute=>33, second=>03, nanosecond=>400e6,
    time_zone=>'Europe/Paris' );
my $diff_sec = $dt1->subtract_datetime_absolute($dt2)
    ->in_units('nanoseconds')/1e9;
print "$diff_sec s\n";
__END__
-53.4 s