Astronomical/electronic timer switch with simple, intuitive programming of 60 switching times, either astronomical or electronic. The astronomical time control allows for automatic switching with a selectable time offset from sunrise and sunset. The astro function can be blocked independently of sunrise and sunset; for example, the lighting can be turned on no later than 8:00 PM. The electronic time control enables automatic switching after a preset time with automatic changeover between summer and winter time. It features a manual switch preview for permanent on and off via a manual switch. Programmable without a power connection, it allows for location determination by selecting the nearest city or entering coordinates, as well as other useful functions. Program security is ensured by a PIN code. Designed for 35 mm DIN rail.