Abstract: Apparatus and methods are provided for use with a Shabbat-elevator inside a building, including an elevator transmitter configured to be placed in a vicinity of the elevator and to transmit a signal. At least one repeater is placed on a given floor of the building, the repeater including a receiver that is configured to receive the signal from the transmitter, when the elevator is at the given floor. A control unit is configured, in response to the signal, to determine a time interval until the elevator is predicted to next be at the given floor. A display unit displays an indication of when the elevator is predicted to next be at the given floor, based upon the determined time interval. Other applications are also described.