2 minor comments on your code

if ($d2 >= $1) {
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i guess $1 is a typo.

print "\n $d2 is greater or equal to  $d1\n";
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your print statements are equal.

one recommended module on CPAN is DateTime

from the DateTime docs:

DateTime->compare( $dt1, $dt2 )
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Compare two DateTime objects. The semantics are compatible with Perl's sort() function; it returns -1 if $d1 < $d2, 0 if $d1 == $d2, 1 if $d1 > $d2.

use strict;
use warnings;
use feature 'say';
use DateTime;

my $d1 = DateTime->new(
    year      => 2019,
    month     => 8,
    day       => 1,
    time_zone => 'America/Chicago',
);

my $d2 = DateTime->new(
    year      => 2019,
    month     => 6,
    day       => 8,
    time_zone => 'America/Chicago',
);
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say DateTime->compare( $d1, $d2 )

say DateTime->compare( $d1, $d2 ) > 0
    ? $d1->ymd .' is greater than ' . $d2->ymd 
    : $d2->ymd .' is greater or equal to ' . $d1->ymd;
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update: sorry, my fault <no excuse>