Hi,

I eschew Time::Piece for date math. It has some weird internal issues with constants and overloading, which I don't completely understand, but people I trust including some wiser and more experienced Monks than I, recommend against it. (See e.g. comments in this discussion.)

Alternate solution using Time::Moment which IIUC is as accurate as DateTime but considerably lighter-weight:

use v5.10;
use Time::Moment;

my $tm1 = Time::Moment->new(year => '2019', month => '6', day => '1');
my $tm2 = Time::Moment->now;

$tm1 = (say $tm1->strftime('%c') and $tm1->plus_months(1)) while $tm1 
+<= $tm2;
[download]

Mon Jul  1 00:00:00 2019
Thu Aug  1 00:00:00 2019
Sun Sep  1 00:00:00 2019
Tue Oct  1 00:00:00 2019
Fri Nov  1 00:00:00 2019
Sun Dec  1 00:00:00 2019
Wed Jan  1 00:00:00 2020
[download]

Hope this helps!