@ngdoc error
@name ngModel:datefmt
@fullName Model is not a date object
@description

All date-related inputs like `<input type="date">` require the model to be a `Date` object.
If the model is something else, this error will be thrown.
AngularJS does not set validation errors on the `<input>` in this case
as those errors are shown to the user, but the erroneous state was
caused by incorrect application logic and not by the user.