title: Can I change current DateTime WITHOUT effecting other programs?
body: <p>I need to simulate an App that references DateTime.utcNow.</p>
  
  <p>I would like to change the time that is returned, but do not want to mess up my PC and taskschedulers etc.</p>
  
  <p>Is it possible to change what is returned from DateTime.Now and DatetIme.utcNow, purely within contexts of the program itself?</p>