What is Leap Year?

What is Leap Year ?

Opposite to the concept of “common year”, the leap year is a four-year period according to the Gregorian calendar. That is, a year includes 366 days instead of 365 days. The reason for this is that February has 29 day in every four years. It was first applied in the Julian calendar in 46 BC. The calculation of turning sun’s around the world is known as astronomical year and it takes 365 days and 6 hours. With the accumulation of time periods of 6 hours, one more day occurs every 4 years. In this way, 366 days, that is, the year now occurs. In February 4, which is 28 days for 3 years, it becomes 29 days. The main point of the realization of this event is that the sun does not coincide with a certain day when the sun passes through the same meridian for the second time. In this way, our time and seasons are balanced.

When is the next leap year?

The last leap year was 2016, and the next leap year is 2020! 

Why Add Leap Years ?

If we observe the Earth’s revolution around the sun, it will take about 365 days and 6 hours. But, the modern Gregorian Calendar has only 365 days. According to the calculation, it collects the 6 hours for 4 years and it means 1-day. That’s the reason off adding leap years in every 4 years at the end of February. In addition, if you see the day of February 29 on the calendar, it means you are living in a leap year basicly.

Historical Background of Leap Year

Normally, a year takes 365 days for the Gregorian Calendar. The leap year application was implemented for the first time in the calendar type known as the Julian Calendar in the year 46 AD. This situation causes us not to live on the 29th of February each year. So much so that dozens of people born on February 29 can celebrate their birthdays for one time in every four years.

Calculation of Leap Year

Years can now be calculated in detail and effectively by governments and individuals empowered at various levels of government. In simple terms, we can say that leap years are years that are four and multiples of four. As a general rule, we can accept the years that are multiple of 400 as a leap year. In addition, only the non-multiples of 100 and 4 are leap years. For example, the years 1888, 1892, 1896, 1904, 1988, 1992, 1996, 2004 are leap years. The year 2000 is a good example of leap year, but the year 1900 (because it is the multiple of 100 but not 400’s) is no longer a leap year. The Julian Calendar and developed Iranian calendars also have leap years with similar rules. For example, 1200, 1600, 2000 are leap years, but 1700, 1800 and 1900 are not leap years. The reason why only fully divisible by 400 is now considered a year is to eliminate the error caused by an astronomical year being approximately 365,242 days instead of 365.25. In order to make the calculation even more sensitive, the years that are divided into 4000 without any residues are no longer considered as leap  years. For example, although the years 4000, 16000 and 24000 can be fully divided into 400, the years will no longer be accepted as leap years.

When we look at this year, 2019 is not a leap year because it’s not a multiple of 4 or 100. But, if we look at the following year 2020, we would see it meets all of the conditions for the concept of being a leap year mathematically. If we observe it closely, it’s a multiple of 4 and if we know 2000 is a leap year, we can calculate it. So, as a final result, 2000 – 2004 – 2008 – 2012 – 2016 and 2020 are the leap years. Google, which holds the title of the world's most used search engine, added a Doodle by changing the search page at 00:00 at night. This Doodle, made by Google, was created because 2020 is a leap year, and encouraged its users to search for what is now, what is now year, information about the year. The month of February 2020 has 29 days and the resulting residual year calculation corrects that 2020 is a leap year.

Background of Gregorian Calendar

12.5 years after the correction of the calendar in the religious council gathered in Iznik in 325 BC, no new adjustment was made, so a ten-day difference occurred in the settlements. His real name was Vgo Bon Compagni who made re-correction of the calendar in 1582. While he was doing this work, every nation of the nations in the world had been using Ihrani, Kiliti, Kalde, ancient Egypt, ancient Greek, Roman, Chinese Islam, Hindu, Laos, Madagascar, Kamboch or Vietnam calendars. The Pope thirteenth Gregory attempted in the calendar business scientific it was for the purpose of the universal internationalization of a principles-based, correct and common foundation. Pope, a board of physics, astronomy, cosmography professors were realized in Rome on 1582. They determined there was 10 day missing and they decided to pass from October 4 to October 15 in one night suddenly. The calendar after this change was called as “Gregorian calendar” because he contributed greatly to the initiative.

This calendar is based on an approximate value of 365 days 5 hours 47 minutes 48 seconds. This calculation is true with a 3-day error in 10,000 years. According to Gregorian calendar one day includes 23 hours, 56 minutes and 4.09 seconds. The necessity of international relations today, the Gregorian calendar, it is used by almost all world nations due to its accuracy and practicality.

The following table shows the years between 2016-2100.

Year Leap Year
2016 February 29, 2016
2020 February 29, 2020
2024 February 29, 2024
2028 February 29, 2028
2032 February 29, 2032
2036 February 29, 2036
2040 February 29, 2040
2044 February 29, 2044
2048 February 29, 2048
2052 February 29, 2052
2056 February 29, 2056
2060 February 29, 2060
2064 February 29, 2064
2068 February 29, 2068
2072 February 29, 2072
2076 February 29, 2076
2080 February 29, 2080
2084 February 29, 2084
2088 February 29, 2088
2092 February 29, 2092
2096 February 29, 2096

To ensure consistency with the true astronomical year, it is necessary to periodically add in an extra day to make up the lost time and get the calendar back in synch with the heavens. Now we have prepared an extensive list of content. You can get help about "when is the next leap year?" from the following websites.

Next Leap Day: February 29, 2020 - Time and Date

A Leap Day, February 29, is added to the calendar during leap years. This extra day makes the year 366 days long – not 365 days, like a common year. ... Without an extra, or intercalary, day on February 29 nearly every four years, we would lose almost six hours every year.

https://www.timeanddate.com/date/leap-day.html

When is the next leap year? | Earth | EarthSky

Bottom line: 2019 isn't a leap year, because it isn't evenly divisible by 4. The next leap day will be added to the calendar on February 29, 2020.

https://earthsky.org/human-world/why-do-we-need-leap-years

When is the Next Leap Year? | Leap Year Dates, History, Folklore

Find out when the next Leap Day will be and how to calculate Leap Years! Plus, we’ll explain why we have Leap Years and some fun folklore. ... A “Leap Day” is the extra day—February 29—which is added nearly every 4 years to today’s Gregorian calendar.

https://www.almanac.com/content/when-next-leap-year

When is the next leap year and why do we have them?

Get ready for the next leap day and find out why we actually have them in our handy, informative guide.

https://metro.co.uk/2018/01/28/next-leap-year-2-7266790/

Leap Year 101 – Next, When, List, Days, Calendar, Years, Calculation, Last, Rules

2016 is a leap year, which means that it has 366 days instead of the usual 365 days that an ordinary year has. An extra day is added in a leap year—February 29 —which is called an intercalary day or a leap day.

https://www.infoplease.com/leap-year-101-next-when-list-days-calendar-years-calculation-last-rules

List of Leap Years - kalender-365.de

A leap year is every 4 years, but not every 100 years, then again every 400 years. This year 2019 isn't a leap year. The last leap year was 2016, the next will be 2020.

https://kalender-365.de/leap-years.php

When is the next leap year? Why do we have them and when was the last one?

OUR calendars have an extra day in February every four years. This is known as a leap year – but what are they and what if you're unlucky enough to be born of February 29? Here's the lowdown..

https://www.thesun.co.uk/news/2963230/leap-year-days-next-one/

Leap year - Wikipedia

A leap year is a calendar year containing an additional day added to keep the calendar year ... one day of the week from one year to the next, the day of the week in the 12 months following the leap day (from March 1 through February 28 of..

https://en.wikipedia.org/wiki/Leap_year

What is a leap year? - NBC News

Leap years come every four years. Next year will be a leap year, which means that February, 2020 will have 29 days instead of 28.

https://www.nbcnews.com/mach/science/what-leap-year-ncna972131

When's The Next Leap Year? - Farmers' Almanac

The last leap year was 2012. The reason for the extra day during some years has to do with our need to keep our modern day Gregorian Calendar in alignment with the Earth’s revolutions around the Sun.

https://www.farmersalmanac.com/whens-next-leap-year-20576

List updated by 10/18/2019.