title: Primeng Calendar: Do not reject DateTime if Time is missing
body: <p>I am using the calendar form PrimeNG. I need to be able to select the time as well so I have set <code>[showTime]="true"</code>. So far so good. The component is working fine.</p>
  
  <p><strong>My problem:</strong></p>
  
  <p>My users want to be able to use the input field to type a date/time combination and hit enter to apply the change.
  However, when omitting the time, the input is completely rejected on blur. I would rather have it set to 00:00 if the input was just a date without a time. How would I do that?</p>
  
  <p>I could not find a way to alter the internal date validation.</p>