Subject: date(1) Produces ISO 8601 it Won't Take Back.

From: Ralph Corderoy <[email-masked]>
Date: Fri, 27 Jul 2018 12:34:11 +0100

Hi,

coreutils 8.29-1 on Arch Linux.

    $ date -uIs -d @-62135596801
    0000-12-31T23:59:59+00:00                           
    $ date -uIs -d @0000-12-31T23:59:59+00:00
    date: invalid date ‘@0000-12-31T23:59:59+00:00’     
    $

If date thinks it's valid ISO 8601 when it outputs it,
I'd expect it to be considered valid input to take back.

Cheers, Ralph.