clearing picker inputs makes form invalid => can't submit form

[jimmywarting]

when ppl how has a date picker (eg: chrome) decides to clear the field on a input that is not required results in a invalid form

if datetime-input starts empty, its valid
if you pick a date it's valid
but if you clear it, it will be invalid

[Narretz]

This sounds similar to #12207 and #11622. Seems to be a bigger problem.

[gkalpak]

This seems indeed to be the same issue as #12207.

[jimmywarting]

Yupp, can close this.