public void checkRents() {
		Date currenttime = null;
		try {
			currenttime = date.parse(date.format(new Date()));
		} catch (ParseException e) {
			e.printStackTrace();
		}
		if (currenttime != null) {
			for (RentSign rent : rentsigns) {
				this.checkRent(rent, currenttime);
			}
		}
	}