I wasn't familiar with enum in perl as opposed to C, so I found this interesting to replicate and then supplement from the examples given in enum.pm:

date is 0
time is 1
2020-03-21 2:00 pm
           3:00 pm
2020-03-22 2:00:pm
6 is SIX
pref is 2
date is Months_Feb 1
c is  22
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#!/usr/bin/perl
use warnings;
use strict;
use feature qw{ say };

use enum qw( DATE TIME );

say "date is ", DATE;
say "time is ", TIME;

my @reservations = (
  [ '2020-03-21', '2:00 pm' ],
  [ '2020-03-21', '3:00 pm' ],
  [ '2020-03-22', '2:00:pm' ]
);

my $last_date = "";
for my $reservation (@reservations) {
  print $last_date eq $reservation->[DATE] ? ' ' x 10 : $reservation->
+[DATE];
  say ' ', $reservation->[TIME];
  $last_date = $reservation->[DATE];
}

use enum qw(Forty=40 FortyOne Five=5 Six Seven);

# Yes, you can change the start indexs at any time as in C
say "6 is ", "SIX";

use enum qw(:Prefix_ One Two Three);
## Creates Prefix_One, Prefix_Two, Prefix_Three
say "pref is ", Prefix_Three;

use enum qw(
  :Months_=0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
  :Days_=0   Sun Mon Tue Wed Thu Fri Sat
  :Letters_=20 A..Z
);
say "date is Months_Feb ", Months_Feb;
say "c is  ", Letters_C;
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