Select Code to Download

@HoH{keys %hash} = values %hash

$HoH{$unit_num} = $hash{$unit_num};

  %hash = (
             $unit_num => {
...
  );

  @HoH{keys %hash} = values %hash

  push @{ $HoH{$unit_num}{$event_nm} }, $event_date

  $HoH{$unit_num}            ||= {};
  $HoH{$unit_num}{$event_nm} ||= [];
  push @{ $HoH{$unit_num}{$event_nm} }, $event_date;

print Dumper( \%HoH );