select col1, col3, CONCAT(date, ' ', time) AS startTime...

##</code><code>##


  my $rs = $self->db->resultset('MODELCLASS')->search(undef, {
    select => [
        'col1', 'col2', 'date' . ' ' . 'time'
      ],
      as => [ qw/
        id title time
      /],
      rows => 10
    });