Q&A for How to Calculate Leap Years

No, there is still a small error that must be accounted for. To eliminate this error, the Gregorian calendar stipulates that a year that is evenly divisible by 100 (for example, 1900) is a leap year only if it is also evenly divisible by 400. For this reason, the following years are not leap years: 1700, 1800, 1900, 2100, 2200, 2300, 2500, 2600. This is because they are evenly divisible by 100 but not by 400.

Each year is technically 12 months and a fraction of a day, close to .25. Every four years, the fraction is compiled to create a whole day and added to that year.

These numbers resulted from complex calculations that were done to ensure that, over the long term, our calendar years would stay as close as possible to the actual time it takes the earth to revolve around the sun. This includes somewhat arbitrary additions/subtractions of an extra day to certain years. Generally speaking, leap years occur every 4 years, and they are the years divisible by 4 (2000, 2004, 2008, etc.). However, for three out of four years divisible by 100, the leap year thing is skipped; only those years divisible by 100 that are also divisible by 400 remain leap years (so: 1600 was a leap year, while 1700, 1800, and 1900 were not; 2000 was a leap year, while 2100, 2200, and 2300 will not be).

If a year is divisible by 100 but not 400, then it is not a leap year. 1900 is divisible by 100, but not 400.

Because, just as a 365-calendar undershoots measuring our trip around the sun (by about .25 days every year, to be more precise), over time, adding a whole day every 4 years overshoots it a tiny bit as well. This is why we add a day every 4 years, but we pull it back a bit around every 100 years. It's all meant to find the most easily calculated plan to measure our days according to the solar system.

Because 1604 is divisible by 4, and it's not divisible by 100 or 400. Leap years are needed to keep our modern Gregorian calendar in alignment with the Earth's revolution around the Sun.

See Step 3. If a year is divisible by 100, it is not a leap year. The '00' years are the exception to the 'every 4 years' rule. So 1896 was a leap year, 1900 was not, and 1904 was.

There were 473 leap years between 100 and 1985. Back then they used the Julian calendar, which means every 4 years was considered a leap year, but the Gregorian calendar was adopted in 1582. The Gregorian calendar rule is, if the year is divisible by 100 but not divisible by 400, then it will not be a leap year.

No. As it's clearly not divisible by 4, it violates the very first step in calculating the leap year.

While this might work for some, it isn't recommended, as the Summer Olympic Games take place every four years, including non-leap years like 1900.

For the most part. Centurial years are only leap years if they're divisible by 400; for example, the year 1700 (which is divisible by 4) was not a leap year, while the years 1600 and 2000 were.

2556 / 4 = 639 check if it is even divisible by 4. 639 / 100 = 6.39 check if it is not even divisible by 100. Thus 2556 is a leap year.

Your age will be the same as normal, nothing changes as far as how many years old you are, if you want to count days then check is you were born before February 29th or after February 29th, if you were born before then count and extra day, it not then don't.

2024 is divisible by 4 and it’s not divisible by 100. 2024 will be a leap year.

In the Julian calendar every year divisible by 4 is a leap year. 1800 was a leap year according to the Julian calendar since 1800 is divisible by 4.