IT might seem like we've been doing it forever, but when clocks spring forward on Saturday it will only be for the 99th time.
Along with the centenary of the Easter Rising next year, another less well-known anniversary will be marked - the day when Irish and British time was synchronised.
Up until the Rising, Dublin meantime - the "legal" time for the country - was based around the local meantime at Dunsink Observatory outside Dublin. This meant it was about 25 minutes and 21 seconds behind Greenwich Mean Time.
However, in 1916 the time difference between Ireland and Britain was deemed inconvenient for telegraphic communication.
Hence the Time (Ireland) Act in 1916 declared Irish time would be the same as British time.
This and why the clocks change for 'summer time' are subjects that have fascinated Maynooth University researcher, Dr David Malone, who has chronicled the history of Daylight Saving Time (DST).
He traces the history of putting the clock forward to World War I, when it was introduced in order to save energy and resources.
"The idea was first introduced by the Germans during the War and subsequently adopted by Britain in 1916, with the United States following in 1918. At the time Ireland was under British rule, so it was simply implemented here in parallel," Dr Malone said.
The rationale behind changing the hour for the summer and winter seasons is re-evaluated every few years by the EU.
Dr Malone said there were many arguments for and against, ranging from reducing energy and costs, maximising daylight hours during the warmer summer months, reducing traffic accidents and crime, impacting on mental health, and that air quality in Mediterranean countries can be better in the evenings.
"While the arguments have changed, the EU is still positive about it, particularly because it gives more daylight in the evenings for our leisure activities."
And so, for now, DST continues to come into effect from the last Sunday in March to the last Sunday in October.
That means an hour less in bed for everybody this weekend.