Is 1646 a Leap Year or a Common One? Does It Have 365 or 366 Days? The Algorithm and Steps To Calculate. The Last Leap Year Before 1646. The Next Leap Year After 1646. Leap Year Calculator

Is 1646 a leap year or a common one? The last leap year before 1646 and the next leap year after 1646

The leap year algorithm. The three conditions to check in order to know whether a year is a leap or a common one

1) A year that is divisible by 4 (no remainder when divided by 4) is a leap year:


1646 is not divisible by 4 (there is a remainder when divided by 4).


We could have stopped at this step.

The year 1646 is not a leap year but a common one.

It does not meet this condition.


2) In addition to step 1 above: If the year is divisible by 100 (no remainder when divided by 100) then it isn't a leap year:


1646 is not divisible by 100 (there is a remainder when divided by 100).


3) In addition to step 2 above: If the year is also divisible by 400 (no remainder when divided by 400) then it's a leap year:


1646 is not divisible by 400 (there is a remainder when divided by 400).


1646 is not a leap year, it's a common year.
The last leap year before 1646: 1644.
The next leap year after 1646: 1648.

What is a leap year?

A leap year has 366 days. 1646, being a common year, has 365.

In a leap year the month of February has 29 days. February 29th is a valid date.

In a common year the month of February has 28 days. February 29th, 1646 does not exist.

Gregorian calendar (modern, civil)

The first year in the actual calendar (also called Gregorian, modern, civil) was 1582. Before this year another calendar (Julian) was in use, with different rules.

Not all the countries adopted the Gregorian calendar at the same time, in 1582. The adoption process took hundreds of years and is not even now complete.

The actual Gregorian calendar will get out of sync by 1 day with the astronomical calendar around the year of 4818 (after ≈ 3236 of years from its creation in 1582).

How often do the leap years occur?

Nearly once every four years is a leap year. More exactly, leap years occur 97 times in every cycle of 400 years.

Why do we need leap years in our calendar?

Leap years keep the calendar year in sync with the astronomical year, preventing us, for example, from celebrating Christmas in the month of November.



More operations with Leap Years:

The last leap year before 1646: 1644.

The next leap year after 1646: 1648.

Is it a leap year? The last and the next leap year, before and after the year

The leap year algorithm. The three conditions to check in order to know whether a year is a leap or a common one:

1) A year that is divisible by 4 (no remainder when divided by 4) is a leap year.

2) But if the year is also divisible by 100 (no remainder when divided by 100), it's not a leap year, unless....

3) ... Unless it's divisible by 400 (no remainder when divided by 400).

Latest checked up years / Is it a leap year or a common year?

Is 1646 a leap year or a common year? When was the last leap year before 1646? When is the next leap year after 1646? Dec 03 18:40 UTC (GMT)
Is 1746 a leap year or a common year? When was the last leap year before 1746? When is the next leap year after 1746? Dec 03 18:39 UTC (GMT)
Is 2023 a leap year or a common year? When was the last leap year before 2023? When is the next leap year after 2023? Dec 03 18:39 UTC (GMT)
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Is 2016 a leap year or a common year? When was the last leap year before 2016? When is the next leap year after 2016? Dec 03 18:38 UTC (GMT)
Is 1682 a leap year or a common year? When was the last leap year before 1682? When is the next leap year after 1682? Dec 03 18:38 UTC (GMT)
Is 2116 a leap year or a common year? When was the last leap year before 2116? When is the next leap year after 2116? Dec 03 18:38 UTC (GMT)
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Is 2015 a leap year or a common year? When was the last leap year before 2015? When is the next leap year after 2015? Dec 03 18:37 UTC (GMT)
Is 3916 a leap year or a common year? When was the last leap year before 3916? When is the next leap year after 3916? Dec 03 18:37 UTC (GMT)
Is 4220 a leap year or a common year? When was the last leap year before 4220? When is the next leap year after 4220? Dec 03 18:37 UTC (GMT)
Is 2424 a leap year or a common year? When was the last leap year before 2424? When is the next leap year after 2424? Dec 03 18:36 UTC (GMT)
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All the users checked up years / Leap Years or Common Years

Leap Years. Common Years. What are they and why do we need them? The leap years algorithm.

What is a leap year? What is a common year?

A leap year contains 1 extra day, February 29th, over an ordinary year, 366 vs. 365.

How often do the leap years occur in the calendar?

Nearly once every four years, 97 leap years at every 400 years.

Why do we need leap years?

They keep the calendar year synchronized with the astronomical year, preventing us, for example, from celebrating Christmas in November.

The leap years algorithm.

Every year that is evenly divisible by 4 is a leap year, except for years that are evenly divisible by 100, but these years are leap years if they are evenly divisible by 400:

Examples of leap years.

  • Leap years multiples of 4 but not of 100 nor of 400: 1992, 1996, 2004, 2008, 2012, 2016, 2020, 2024, 2028;
  • Common years (NOT LEAP YEARS) multiples of 100, but not of 400: 1700, 1800, 1900, 2100, 2200, 2300;
  • Leap years multiples of 400: 1600, 2000, 2400.

Articles on the leap years

1. What is a leap year? What is a common year?

2. How often do the leap years occur in the calendar?

3. Why do we need leap years?

4. Leap years algorithm. Examples.

5. When did the actual concept of the leap year originate?

6. The modern (Gregorian) calendar and the Julian one. Julian calendar adjustment

7. How accurate is the Gregorian calendar, based on the leap year algorithm?


List of all the leap years between 1582 and 4818.

Leap years calculator. Is it a leap year or a common one?