Backspace key don't work for fields Date, Time, and DateTime. Causes "invalid value" after publish, and makes field uneditable by pickers.

Prerequisites

1. Content type with fields:
   1. String - Name
   2. DateAndTime without property Require
   3. Date without property Require
   4. Time without property Require

Steps:

1. Go to Content > Content structure > Create
2. Click link with content type from Prerequisites
3. Fill DateTime field
4. Remove value from field with backspace key
5. Click Publish button
6. Repeat for fields Data and Time

Actual result:

Message "This value is not valid" by the cleared field. Field filled with "NaN" values.

Expected result:

Publish succesfull.