Jens was 60 when he started constructing the clock, but the story starts when he was only 25. In Strasbourg, the young locksmith saw an astronomical clock with a perpetual calendar in a cathedral.

If the workings of a mechanical timepiece give you a thrill, prepare to be blown away by this over-the-top astronomical ... clock from a few years back; now seems like a great time to go back ...

The leap second – units of time added to the atomic clock every few years to remain synchronised with astronomical time – should be replaced with a leap minute added far less frequently ...

As winter progresses, and days seem impossibly short, don't forget that Daylight Saving Time will soon be here. Here's when to change clocks this year ...