Summary

  • The UK government is asking who uses the MSF radio time signal, how much they rely on it and whether it is a primary source or a resilience measure.
  • MSF is a one-way 60 kHz broadcast. The government says the signal cannot tell it who receives it; NPL says it runs continuously from Anthorn and lists scheduled maintenance outages.

Britain's time signal has a peculiar customer-service problem: it cannot tell the government who its customers are. No receiver checks in. No handset pings the mast to say, “Still here, still using Tuesday.” The signal simply leaves Cumbria and keeps going.

The Department for Science, Innovation and Technology's National Positioning, Navigation and Timing Office has opened a call for evidence about MSF, the UK's long-wave radio time and frequency broadcast. Published on 26 October, it asks organisations and individuals who use, used or might benefit from the service to explain what they do with it. The form has nine questions. The policy problem behind them is bigger than a survey: how do you plan for infrastructure whose audience is invisible to its transmitter?

The government's own description supplies the oddity. MSF, also known as Rugby Time or Radio Time, is a terrestrial broadcast that gives UK time traceable to UTC(NPL), the national time scale generated by the National Physical Laboratory. Compatible receivers across much of the country can decode it. The service is one-way, so it carries no information about who receives or relies on the signal.

That makes a small clock on a kitchen shelf and a timing input buried in a business process look the same from the mast's point of view: silent. The government explicitly asks for the full range, from radio-controlled wristwatches and school clocks to business-critical and safety-critical applications. It also asks whether MSF is the primary source of time and frequency or a way to add resilience.

That distinction matters. A clock that resets after a reception gap and a system that uses a terrestrial timing feed as one layer in a larger design do not create the same operational question. Yet neither can be counted by the transmitter. The call is an attempt to collect the human and organisational evidence that the radio path cannot return.

NPL provides the operating facts. It says the 60 kHz signal is available 24 hours a day and carries a time and date code. It is transmitted from Anthorn Radio Station in Cumbria by Babcock International under contract to NPL. NPL monitors the broadcast against UTC(NPL) and corrects it when necessary. The same NPL page lists scheduled shutdowns for maintenance on the masts and antennas, including a four-hour full shutdown on 10 December 2026.

The maintenance notice describes ordinary transmitter upkeep and gives users a practical question to answer: what happens in a system that depends on this signal during the planned break? NPL also notes that nearby metalwork and local electrical interference can make reception difficult. A signal may be on air while an individual receiver cannot get a clean reading. Availability at the transmitter and usable time at the far end are different measures.

The national PNT office says it wants people to have access to a range of services so they are less dependent on a single source. NPL describes a wider set of methods too: MSF radio, internet time via Network Time Protocol and NPLTime over fibre, while its National Timing Centre programme develops a nationally distributed timing infrastructure. Each method has its own delivery path and operating requirements.

The evidence call therefore sits between two kinds of knowledge. The operator can report what the transmitter sends, how it is monitored and when maintenance is planned. Only users can say whether the signal is decorative reassurance, an everyday convenience, a backup or a component in a process that someone will notice when it disappears. The call asks for that distinction before future policy is shaped.

The mast knows the time. Its users have to tell the state why they care.