List of Leap Years

The reformed Julian calendar, now known as Georgian calendar, is followed all over the world today. The Georgian calendar has two types of years, the common year and the leap year. The common years are years that have 365 days, but, a leap year has an extra or intercalary day, that makes the year have a total of 366 days.

This extra day is added to the year to synchronize the calendar year with the solar year. This means, it tries to match the length of time, the earth requires to complete its orbit around the sun, that is, 365¼ days. The solar year is about 11 minutes less than 365¼ days in length. Therefore, to compensate the discrepancy, the extra day or leap year is omitted three times every four hundred years.

History of the Calendar
The first calendar was devised in 735 BC by Romulus, the first Roman king. This Romulus's calendar had 10 months instead of the usual 12 months. The 10 months in Romulus's calendar were named as:

• Martis, named after Mars, the Roman god of war
• Aprilis, derived from the Latin word aperite, meaning 'to open', just as the flowers open during this month.
• Maius, named after the mother of Mercury, Maia.
• Junius, named after the queen of gods, Juno

The Latin numbers were used to derive the names from the fifth months onwards like:

• Quintilis
• Sextilis
• September
• October
• November
• December

As this calendar proved to be inaccurate compared to the solar year, King Numa added two extra months to the year and brought the number of days to 355 with Janaruis, named after Janus, the two faced god and Febuarius, derived from Febura, a Roman feast. This still had many problems and could not be made right by adding extra months. This confusion was cleared by another Roman emperor, Julius Caesar. He introduced the Julian calendar in 46 BC. He involved the best philosophers to correct the calendar. They calculated the year should have 365¼ days. This could be made possible by following a cycle of three years with 365 days and followed by one leap year of 366 days. Julius Caesar added 30 and 31 days to consecutive months. Thus March has 31 days, April 20 and May 31 days and so on. January, the month near to the winter solstice, was made the first month of the year. He added only 29 days in the month of February in a common year and the intercalary day was inserted in February every fourth year. Julius Caesar was honored by the Roman Senate by renaming Quinitis as 'Julius' (now June).

After the death of Julius Caesar, the priest made a mistake and started to add leap years every three years. It was corrected by Emperor Augustus in 8 BC. Augustus, too was honored by the Romans by renaming Sextilis as 'Augustus'. Emperor Augustus, was not happy with his month having fewer days than the month of Caesar. He therefore, added an extra day in his month making it 31 days. Thus, one day was subtracted from February, making it 28 days long in a common year and 29 days long during the leap years. This Julian calendar was followed without any change for many centuries.

But, this calendar still had its flaws. The average year of was 365.25 days long and the solar year length is 365.242216 days. This made the Julian calendar 11 minutes and 14 seconds longer. This little extra added up over the centuries, and lead to the vernal equinox fall on March 11 rather than March 21, during the 16th century. Thus, Pope Gregory XII, moved the date by 11 days and made an exception to the rules of leap years. Now, according to the new rule, a century is a leap year only if it is divisible by 400. Thus, the average length of a Gregorian year is now 365.2425 days. The following table gives a list of leap years from the 1800s till the 2400s.

List of Leap Years in 1800	List of Leap Years in 1900	List of Leap Years in 2000	List of Leap Years in 2100	List of Leap Years in 2200	List of Leap Years in 2300
1804	1904	2004	2104	2204	2304
1808	1908	2008	2108	2208	2308
1812	1912	2012	2112	2212	2312
1816	1916	2016	2116	2216	2316
1820	1920	2020	2120	2220	2320
1824	1924	2024	2124	2224	2324
1828	1928	2028	2128	2228	2328
1832	1932	2032	2132	2232	2332
1836	1936	2036	2136	2236	2336
1840	1940	2040	2140	2240	2340
1844	1944	2044	2144	2244	2344
1848	1948	2048	2148	2248	2348
1852	1952	2052	2152	2252	2352
1856	1956	2056	2156	2256	2356
1860	1960	2060	2160	2260	2360
1864	1964	2064	2164	2264	2364
1868	1968	2068	2168	2682	2368
1872	1972	2072	2172	2722	2372
1876	1976	2076	2176	2762	2376
1880	1980	2080	2180	2802	2380
1884	1984	2084	2184	2842	2384
1888	1988	2088	2188	2882	2388
1892	1992	2092	2192	2922	2392
1896	1996	2096	2196	2296	2396
	2000				2400

The Georgian calendar was adopted in 1752 in Great Britain. Thus, leap years are those, that are divided by 4 and leap centuries are those centuries that are divisible by 400. The chances of gaining one extra day will take around 3,300 years in the current Georgian calendar. If you are wondering when is the next leap year, then according to the above list of leap years, 2012 will be the next leap year. I hope you have understood what is a leap year and the history behind leap years. I'll end my list of leap years with a poem dedicated to leap years by an anonymous poet:

Thirty days hath September,
April, June and November.
All the rest have thirty-one,
Excepting February alone,
And that has twenty-eight days clear
And twenty-nine in each leap year.