Love it or hate it, daylight savings is upon us again.

As clocks move an hour forward on September 29, many of us will be adjusting to longer afternoons, disrupted sleep, and the usual range of mixed feelings.

Why do we have daylight saving?

Because the Earth is on a tilt (of about 23 degrees, for those curious), we are exposed to more sun during summer and less during winter.

That means the days are longer during the warmer months and shorter in the colder months.

Daylight saving is intended to make the most of those long daylight hours. It means an extra hour of light on summer evenings, rather than super early in the mornings when hardly anyone is awake to enjoy it.

How long have we been doing this? 

New Zealand first observed daylight saving in 1927.

However, the dates that clocks went forward and back, and the amount of time they were changed, varied over the following years.

In 1941, daylight saving was extended year-round under emergency regulations to help save energy during World War II.

Five years later, daylight saving time (or summer time as it was then known) was adopted as standard time, effectively discontinuing daylight saving.

In 1975, daylight saving was introduced again.

It was extended to its current dates - from the last Sunday in September to the first Sunday in April - in 2007.

When will daylight saving time start again?

Clocks will go forward one hour at 2am on Sunday, September 29.