DateTime Logic

Question

HOw to convert this logic to C # below from visual basic 6. I am not for you how you suppose to do the logic below


 //            If ServiceTimeStart >= #12:00:00 AM# And ServiceTimeStart < #12:00:00 PM# Then
 //   ServiceTime = "M"
 //ElseIf ServiceTimeStart >= #12:00:00 PM# And ServiceTimeStart < #6:00:00 PM# Then
 //   ServiceTime = "A"
 //ElseIf ServiceTimeStart > #6:00:00 PM# And ServiceTimeStart < #12:00:00 AM# Then
 //   ServiceTime = "E"
 //ElseIf IsNull(ServiceTimeStart) Then
 //  ServiceTime = "D"
 End If