>>522 Perl5

use Time::Piece;
for (<DATA>) {
 chomp;
 my $t;
 eval {$t = Time::Piece->strptime($_, '%Y/%m/%d')};
 $t //= 'Invalid';
 print "$_: $t\n";
}
__DATA__
1970/01/05
1990/12/31
2019/04/28
2019/05/01
1920/02/29
0000/13/32


実行結果
1970/01/05: Mon Jan 5 00:00:00 1970
1990/12/31: Mon Dec 31 00:00:00 1990
2019/04/28: Sun Apr 28 00:00:00 2019
2019/05/01: Wed May 1 00:00:00 2019
1920/02/29: Sun Feb 29 00:00:00 1920
0000/13/32: Invalid