Time::Piece is returning a wrong value

Question

I am trying to convert date from yymmdd to YYYY-MM-DD with Time::Piece module. With the input as Nov 31, 2000 (20001131), I am getting output as 2000-12-01. In reality, Nov 31 doesn't even exists.

use Time::Piece;
my $dt_str = Time::Piece->strptime('20001131', '%Y%m%d')->strftime('%Y-%m-%d');
print $dt_str;

Am I missing something here?

Answer 1

Internally, it does only rough validation and error reporting, and then performs the same transformations as POSIX::mktime does; any days beyond the end of a month will just cause it to advance the produced date into the next month. This does seem a little inconsistent; since it allows that for days, I'd also expect it to treat '20005931' as '2004-12-01', but instead it errors out.