title: How to set the default value of DateTime to empty string?
body: <p>I have a property called Raised_Time, this property shows the time at which alarm is raised in datagrid Cell. I don't want to show anything in the datagrid cell when user creates any alarm, it just display the empty cell.</p>
  
  <p>I googled in the internet and found that the default value of DateTime can be set using DateTime.MinValue and this will display MinValue of datetime i:e "1/1/0001 12:00:00 AM". </p>
  
  <p>Instead I want that the datagrid cell remain blank until alarm is raised, it don't show any time.</p>
  
  <p>I think datatrigger can be written in this case. I am not able to write the datatrigger for this scenario. Do I need a converter also that checks if DateTime is set to DateTime.MinValue the leave the datagrid cell blank??</p>
  
  <p>Please help!!</p>