Question: How long is a solar year?
Answer: 365 days, 5 hours, 48 minutes and 46 seconds – We have leap years to make up for the extra hours, minutes and seconds
Today is the 28th of February and, in a typical year, the last. But not this year – 2016 is a leap year. Have you ever wondered how leap years came about? Yes, we all know that there are slightly more than 365 days in a solar year and so we have leap years to make up the difference, but who first noticed, who decided to introduce leap years and why choose to add one day to February rather than to any other month? Well, here at Education Quizzes we got to wondering. Come with us and we’ll explore the history of leap years together…
The famous Julius Caesar was the first to try and bring order to the wayward, ancient Roman calendar. Before him the calendar had only 355 days arranged like this:
- January – 29 days
- February – 28 days
- March – 31 days
- April – 29 days
- May – 31 days
- June – 29 days
- Quintilis (July) – 31 days
- Sextilis (August) – 29 days
- September – 29 days
- October – 31 days
- November – 29 days
- December – 29 days
A rather haphazard arrangement I’m sure you’ll agree, and caused by the superstitious Roman dislike of even numbers. All of this meant that the calendar was 10 days too short and so New Year’s Day might fall in summer one year and in autumn the next – hardly befitting of the most powerful and civilised culture the world had yet seen!
Caesar set about reforming the Roman calendar and he introduced the Julian calendar to take its place in 46 BC. He set the length of months to their current values and introduced the additional 29th February every 4 years – the leap year. Why did he choose February to be the shortest month? Well, it already was the shortest. It was also a special month to the Romans, being the last in their year (New Year’s Day came in March) and it was a time of purification and the Februa festival.
Julius Caesar’s calendar was impressively accurate and it endured for over 1,500 years. There was however a small problem – Caesar’s calendar was 11 minutes and 15 seconds a year too long. Not much, but it all adds up! By the 16th Century the calendar was 10 days fast.
It was Pope Gregory XIII who set things straight. He removed 10 days from 1582 AD (October 15th followed October 4th that year) and changed the rule for leap years. From then on an extra day would be added to century years (200, 300, 400 etc.) only if they were divisible by 400 as well as by 4. That is why 2000 AD was a leap year but 1900 was not and 2100 will not be either.
The Gregorian calendar is a little odd. Each year starts on a different day of the week and a new calendar is needed every year. In addition the solstices and equinoxes do not align with the beginning of the months whose lengths verge on being random.
Many people have proposed alternative calendars, from Napoleon who brought in a year made up of 36 10-day weeks, to the science fiction writer Isaac Asimov who suggested having just four 91 day months to coincide with the 4 seasons. But the length of our year, not to mention the lunar cycles which do not match, make coming up with a ‘tidy’ calendar a very difficult task – one which has eluded even the finest minds since history began.
I myself have come up with various possibilities when daydreaming – 10 36-day months with 5 extra ‘holidays’ (or 6 in a leap year) or 60 6-day weeks also with 5 ‘extra’ days. Both of these would be standard calendars which only change in leap years and every ‘date’ would fall on the same weekday every year. Childish pipe-dreams you may think – and you may be right – but a harmless way to amuse myself! Why not have a go, perhaps with your children? You just might manage what no-one else has been able to … yet.