and clocks in traffic-light facilities. Signal Time signal The DCF77 station signal carries an amplitude-modulated, pulse-width coded 1 bit/s data signal. The same data signal is also phase modulated onto the carrier using a 512 bit long pseudorandom sequence (direct-sequence spread spectrum modulation). The transmitted data signal is repeated every minute. Current date and time bits; Leap second warning bit; Imminent change of CET to CEST, or vice versa, Announcement bit; Central European Time (CET) / Central European Summer Time (CEST) bit; Abnormal transmitter operation identification bit; Several parity bits. Experimental civil defence emergency signal Since 2003, fourteen previously unused bits of the time code have been used for civil defence emergency signals. This is an experimental service, aimed to one day replace the German network of civil defence sirens. Civil protection and weather forecast signal Since 22 November 2006 the DCF77 transmitter uses bits 1–14 to transmit warning messages and weather information. Under responsibility of the German Federal Office of Civil Protection and Disaster Assistance (the German Bundesamt für Bevölkerungsschutz und Katastrophenhilfe, BBK), warnings to the population can be transmitted using these 14 bits. As a further extension of the information content transmitted by DCF77, appropriately equipped radio clocks can provide a four-day weather forecast for 60 different regions in Europe. The forecast data is provided by and under responsibility of the Swiss company Meteo Time GmbH and is transferred in a proprietary transfer protocol. The same 14 bits are employed in a way that ensures compatibility with the transmission protocols of the warning messages. For decoding the weather forecast data a license is required. Since the bits previously reserved for the PTB are used, older radio clocks should not be affected by the weather data signal. Future and call sign The signal distribution contract between the PTB and the DCF77 transmitter operator Media Broadcast GmbH is periodically renewed. After negotiations in 2021 the PTB and Media Broadcast GmbH agreed to continue the dissemination of the German national legal time for the next 10 years. In order to improve the reliability of the broadcast and also the ease of maintenance by the operator, Media Broadcast GmbH has announced that it will build a second remote-controllable high-performance transmitter in 2022. The facilities will then be completely duplicated on site. In the past the PTB expressed it will initialize new negotiations if modernization activities at the transmitting station to improve the