MSF is the name given to the dedicated time broadcast provided by the National Physical Laboratory in the UK, It is an accurate and reliable source of UK civil time, based on the time scale UTC (Coordinated Universal Time).
MSF is used throughout the UK and indeed other parts of Europe to receive a UTC time source which can be used by radio clocks and to synchronise computer networks by using a NTP time server.
It is available 24 hours a day across the whole of the UK although in some areas the signal can be weaker and it is susceptible to interference and local topography. The signal operates on a frequency of 60 kHz and carries a time and date code which relays the following information in binary format: Year, month, day of month, day of week, hour, minute, British Summer Time (in effect or imminent) and DUT1 (the difference between UTC and UT1 which is based on the Earths rotation)
The MSF signal is transmitted from Anthorn Radio Station in Cumbria but was only recently moved there after residing in Rugby, Warwickshire since it was started in the 1960’s. The signal’s carrier frequency is at 60 kHz, controlled by caesium atomic clocks at the radio station.
Caesium atomic clocks are the most reliably accurate atomic clocks anywhere, neither losing nor gaining a second in several millions of years.
To receive the MSF signal simple radio clocks can be used to display the exact UTC time or alternatively MSF referenced time servers can receive the long-wave transmission and distribute the timing information around computer networks using NTP (Network Time Protocol).
The only real alternative to the MSF signal in the UK is to use the onboard caesium clocks of the GPS network (Global Positioning System) that relay accurate time information that can be used as a UTC time source.