Got it, 2018.2.2 already had the new date control (see 1st link below), but
maybe this issue has been fixed since then. Does the behavior in 2020.1,
where the date is "autocorrected", seem more reasonable to you? You can try
it in the 2nd tab of the Forms Controls (see 2nd link below). BTW, we're
thinking of changing this again, and keeping what the user entered, and
marking it as invalid, instead of trying to autocorrect it.