National Physical Laboratory

MSF Outages


MSF Scheduled Maintenance Periods

The MSF 60 kHz standard-frequency and time signal, broadcast by Babcock on behalf of NPL, is occasionally taken off-air to allow maintenance work on the masts and antennas at Anthorn Radio Station to be carried out in safety. This means that your radio-controlled clock will not be picking up the MSF signal, so may not be working correctly.

One second error in MSF time code on 1-2 April 2015

Please note that, following a planned resynchronisation of the MSF time code generators during the morning of Wednesday 1 April, the time code transmitted by the MSF signal was 1 second late. The error was corrected at around 12:15 BST on Thursday 2 April.

We apologise for any inconvenience this may have caused, and are taking steps to ensure that similar errors do not happen in future.


The dates and times of the forthcoming scheduled maintenance periods are as follows:

  • 11 June 2015 from 10:00 BST to 14:00 BST

  • 10 September 2015 from 10:00 BST to 14:00 BST

  • 10 December 2015 from 10:00 UTC to 14:00 UTC

The duration of each outage period will be kept to a minimum, and the signal may be back on-air prior to the times given above.

In addition to these dates, the signal is likely to be taken off-air for a two-day period during July or August each year, remaining off-air overnight. The dates of this longer outage will be announced on this page and by e-mailed notices to registered users as soon as they are known.

If you wish to be kept informed about planned outages, please complete and submit the E-mailed Notifications of Scheduled Maintenance Periods form.


Find out more about the MSF Radio Time Signal

Some common problems with radio-controlled clocks

Contact: communications@npl.co.uk

Last Updated: 8 Apr 2015
Created: 28 Jul 2010