gistfile1.PL

my $parse_datetime = sub {
    my $ts = shift or return undef;
    return eval { DateTime::Format::W3CDTF->parse_datetime($ts) }
        || eval { DateTime::Format::ISO8601->parse_datetime($ts) }
        || eval { DateTime::Format::Flexible->parse_datetime($ts) }
        || do {
            my $p = DateTime::Format::Natural->new;
            my $dt = $p->parse_datetime($ts);
            $p->success ? $dt : undef;
        };
};