Why does the clock change happen?

The theory behind putting the clocks back is that it gives an extra hour of daylight in autumn and winter.

The clocks first changes in 1916 in the UK, a month after Germany put in place the idea.

William Willet first put forward the idea in 1907, suggesting people were wasting the early daylight of summer mornings by sleeping through them.

Daylight Saving Time was adopted during the world war as a way to boost productivity in the summer months.

Both the spring and autumn clock changes always occur on a Sunday according to an EU directive.