I use a SharePoint list as a data source, in this list I have column of type date. I use this column in an edit form.
The date is editable in this form using the date picker control. This works fine, a user can select a date and the selected date is saved in SharePoint. But when the user deletes the selected date, and submits the form, the deleted date remains in the SharePoint list, it is not updated with a null value, the earlier entered value remains.