Thats how its supposed to be , problem is that it wont show time if item is NULL ie if no time/date stamp has been asigned to DateTime item.
Either create a rule to populate item or create a “manual” input card and use datetime for type .
I did it once , deleted the input card , setup mapdb persistence to carry over in reboot event and added To Today [3.2.0;3.4.9) and [Deprecated] Alarm Clock Rule to make morning tea 
edit : or edit the widget to your liking 