code: def date_to_datetime(date, fraction=0.0):
      
      day_seconds = (60 * 60 * 24) - 1
      total_seconds = int(day_seconds * fraction)
      delta = datetime.timedelta(seconds=total_seconds)
      time = datetime.time()
      dt = datetime.datetime.combine(date, time) + delta
      return dt
docs: fraction is how much through the day you are. 0=start of the day, 1=end of the day.