1. Create a content type with the following specs inside content type group "Content":
Name: Datetime
Identifier: datetime
fields:
Type: Text field
Name: Name
Identifier: name
Type: DateTime
Name: DateAndTime
Identifier: datetime

2. Create on home a content of this content type and on the field Date try to input:
2015-02-32
and publish. It will publish without a warning on the wrong value;
Field will be empty, whereas if the date value is valid it will be properly published.

3. Edit it and try to input the time value:
27:80
and publish. It will publish without a warning on the wrong value;
Field will have a different value than the one (however wrong) that you wrote into it.