Leap Day

Today is not the last day of February, it is tomorrow. This year is a leap year, and tomorrow, February 29th, is a leap day.

Leap days occur every four years. Why?

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It is all about the sun. The earth takes about 365.2422 days to orbit the sun. This is known as a solar year. A normal year is 365 days, so you can see it is not quite long enough. If we had no leap day then our months and seasons would change. In 100 years we would have January in December, and February in January etc. So you could visit Kyoto to take pictures of the autumn colours in New Year. And after 200 years January would be in November; it would slowly and continually get earlier.

It seems to make sense to add an extra day every four years to keep the seasons stable. This day was introduced in 1582 in Italy, Spain Portugal and Poland, but it wasn’t introduced until 1752 in Britain and America.

So everything is OK? No. A solar year is actually 365.242199 years (and can change slightly due to the position of other planets). Adding an extra day every four years is still not accurate. So every 100 years it has been decided there shall be no leap year, consequently any year ending in ’00’ is not a leap year, for example 1800, 1900.

But this is still not enough to be completely accurate, so every 400 years (1600, 2000, 2400 etc.) WILL be a leap year.

Now, for the scientists and geeks the timing is still not quite perfect (by 27 seconds a year, or one day every 3,326 years), but for most of us it is fine.

Is it true that a leap year is a time when ladies can propose to men? This custom was started in Ireland more than a thousand years ago when St Bridget made the suggestion to St Patrick. She originally suggested that ladies should be allowed to propose on the leap day only. In those days life was very much dominated by the males, so this was a very early attempt to balance the situation. St Patrick agreed and so February 29th became a traditional day for ladies to propose.

Maybe one day every four years wasn’t enough, and over time this has been extended to the full leap year. But the leap day is the original day for female proposal, and this day is tomorrow, so ladies good luck, and men beware!

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