code: @SuppressWarnings("deprecation")
  	private Date setHourToZero(Date in) {
  		final Date d = new Date(in.getTime());
  		d.setHours(0);
  		d.setMinutes(0);
  		d.setSeconds(0);
  		// a trick to set milliseconds to zero
  		long t = d.getTime() / 1000;
  		t = t * 1000;
  		return new Date(t);
  	}
docs: Set hour, minutes, second and milliseconds to zero.
  
  @param d Date
  @return Modified date