We can never be on time. We’re either too early or just late.

When we do manage to make it to a meeting on time, we look up at the clock hanging on the boardroom wall and discover that it is obviously not synchronised with ours. Which again makes us either early or late.

If only we could wear the NPL-CsF2 atomic clock on our wrist.

The NPL-CsF2 atomic clock is the most precise clock in existence. It is a caesium fountain atomic clock, where the atoms are tossed up one metre to form a sort of a pendulum.

This makes the NPL-CsF2 so accurate that it only loses or gains one second in 138 million years, that is, one billionth of a second every two months.

There are six exemplars of the CsF2 in the world – one is kept in the UK’s National Physical Laboratory, two in France, and one each in the US, Japan and Germany. These clocks are used as national primary frequency standards, which means that the readings on all six clocks is averaged to calculate the international atomic time and universal coordinated time – these standards are used as time scales worldwide for such critical operations as satellite navigation and time stamping for financial transactions and stock markets.

There’s just one problem though. The NPL-CsF2 atomic clock is about 2.5 metres high and obviously cannot be worn on the wrist. Which means that there’s still no guarantee that you’ll be on time at the office tomorrow morning.