An alternative timelink is here  this reports UTC from the US National Observatory accurate to about 1 second. To achieve more accuracy than this you could try either a 'Rugby' synchronised clock, The Clock on the Teletext Pages which is synchronised to the GPS master clock or else use a GPS satellite receiver with a clock.  

When one is looking for very accurate times ( to less than a couple of seconds ) one has to be careful about which 'flavour' of time you are using. There is a good explanation of the variations in the different flavours here.

As technology advances in leaps & bounds a number of ‘portable’  time standards are now available that will allow you to time events to high accuracy. Some of the options available are:

í     ‘Rugby’ Clocks – now available at very reasonable prices as long as you want a dial or digital display. Getting an output for your computer is more difficult & expensive. All the commonly available ones seem to change to Summer Time. Not sure which ‘flavour’ of time they keep – they sometimes have leap seconds so there are 61 seconds in a minute – this should give you a clue.

í     Teletext Time available on TV’s with Teletext. An alternative is a card that fits in your computer and will synchronise your PC clock to the Teletext time. The BBC version is based on GPS time but probably is modified to change it to a more acceptable flavour.

í     GPS – even the cheap portable GPS’s have very accurate time displays – the time value can often be exported to your computer via a suitable lead & software. The exported value can normally be set to ‘GMT’, Summer Time or any ’Zone Time’. Once again the actual flavour of time needs to be considered. One of the GPS receivers to use for this is the Garmin GPS 35 – this has a One Pulse Per Second Output that is accurate to 1 microsecond ! Beware that this keeps GPS time and you need to consider the difference to other time measurement systems.

The occasional leap seconds can cause problems with precision timing – particularly if your measurement spans the time that a Leap Second is inserted !

If anyone feels capable of describing the various flavours of time & how we should use them and what we need to be careful of how about writing a ‘flavour of time’ page for us.