# Understanding the Solar Calendar: The Debate over Leap Year Frequency

• The_oMeGa
In summary, the solar year is 365.2425 days long and every 4 years we have an extra .96 (and some change) days, leading to a leap year. However, this extra time accumulates every 4 centuries, so we have a rule where century years not divisible by 400 are not leap years. This gives us a pattern of 24 leap days per century, with an extra leap year every 4 centuries to make up for the accumulated time.

#### The_oMeGa

i know this question has probably been answered long ago, but the solar year is 365.24(22?) days long. every 4 years, we have .96 (and some change) left over, therefore we have leap year. but .96 is not 1.00, so shouldn't we "skip" leap year every 25 years? or perhaps, over 100 years, have leap year every 4 years, 5, 5, 5, 4...

the most accurate pattern would be

one leap day every 4 years; one leap day every 5 years; 5; 5; 4; 5; 5; 5; 4; 5; 5; 5; 4; 5; 5; 5; 4; 5; 5; 5; 5|... 21 days/100 years instead of 25/100yrs.

The solar year is 365.2425 days. The modern Gregorian calendar adjusts
By the following Rule:
Every century year (1800, 1900 etc.) that is not divisible by 400 (2000 e.g.) are not leap years. So while 1900, which by the four year rule, would have normally been a leap year, wasn't a leap year, 2000 was, because 2000 is divisible by 400.

The problem with your plan is that the extra .03 day accumlates over 4 years (Every leap year cycle), not one. In a century there are 100/4 = 25 four year cycles.

25* .03 = .75 extra days per century.

If we drop one leap year per century(giving us only 24 leap days/century), that leaves us short .25 days per century. After 4 centuries, we are short one day, so we put back one leap year (Every 4th century has 25 leap days). This gives us the pattern I mentioned above.

Last edited:

## What is a solar calendar?

A solar calendar is a type of calendar that is based on the Earth's position in relation to the sun. It uses the Earth's orbit around the sun to determine the length of a year and the placement of seasons.

## How is a solar calendar different from other calendars?

Unlike lunar calendars which are based on the phases of the moon, a solar calendar is based on the Earth's orbit around the sun. This results in a more accurate measurement of time and allows for a consistent placement of seasons each year.

## What is the most commonly used solar calendar?

The most commonly used solar calendar is the Gregorian calendar, which is used in many countries around the world. It was introduced in 1582 and is based on the solar calendar created by Julius Caesar in 46 BC.

## How does a solar calendar account for leap years?

To account for the extra time it takes for the Earth to complete a full orbit around the sun, a leap year is added to the solar calendar every four years. This keeps the calendar in sync with the Earth's orbit and ensures that the seasons remain consistent.

## What are the advantages of using a solar calendar?

A solar calendar is more accurate than other types of calendars, making it easier to plan and schedule events. It also allows for a consistent placement of seasons, making it easier to track agricultural cycles and plan for weather patterns. Additionally, it is widely used and recognized, making it easier for people from different cultures and countries to communicate and coordinate.