Buzz
Unlike leap years in the Gregorian calendar, which occur every 4 years, with the most recent being 2016, a leap year in the Gregorian calendar, lunar leap years follow a different and irregular cycle.
The methods for determining leap years in the Gregorian and lunar calendars are significantly different. Without careful attention, predicting whether the next year will be a leap year in the Gregorian or lunar calendar can be tricky. So, is 2017 a leap year? And which month is the leap month? Let's delve into the reasons and calculations.
Was 2017 a leap year? Which month was the leap month?
Confirmation: 2017 was a leap year in the lunar calendar, with the leap month falling in June.
The leap month this year falls in June in the lunar calendar, meaning we'll have two June months. The first leap June has 29 days, starting from June 24th (Gregorian calendar), and the second leap June has 30 days, continuing from July 23rd to August 21st (Gregorian calendar).
*Why is there such a difference?
The main reason lies in the difference in calculation methods between the two types of calendars, one based on Earth's orbit around the Sun and the other on the Moon's orbit around Earth.
- Gregorian leap year: One orbit of Earth around the Sun takes about 365.25 days, resulting in an excess of 1/4 day.
After four years, these extra days add up to one extra day (0.25 x 4 = 1 day). Thus, ancient astronomers and calendar makers decided to add an extra day to February as we know it today. This is why every four years we have a Gregorian leap year (366 days).
- Lunar leap year: A lunar month is approximately 29.5 days long. Hence, a lunar year with 12 lunar months totals 354 days (29.5 x 12 = 354 days).
As a result, a lunar year is shorter than a regular Gregorian year by 11 days (354 + 11 = 365 days). When multiplied by three consecutive years, this discrepancy accumulates to 33 days (11x3 = 33 days). Therefore, approximately every three years, a leap month must be added to the lunar calendar to synchronize with the seasons and the solar calendar.
However: as the years accumulate, the lunar calendar still falls behind the solar calendar. Hence, astronomers and calendar makers devised a 19-year cycle. This 19-year cycle consists of 228 Gregorian months (19x12 = 228 months) and 235 lunar months. This leaves a surplus of 7 months between the lunar and solar calendars (228 + 7 = 235).
These seven months will be alternately inserted into the following fixed months in the 19-year cycle:
- Months 3, 6, and 9
- Months 8, 11, 14, 17, 19
However, these months can alternate, making them difficult to grasp without understanding the estimation method.
* How to calculate Gregorian leap years
Determining whether a year is a Gregorian leap year is easy. Just divide the year by 4. If it divides evenly, it's a leap year.
Example: 2016/4 = 504
However, there are exceptions, such as years ending in 00 like 1700, 1800, 1900, and 2000. Only the year 200 is a leap year because the years 1700, 1800, and 1900 are not divisible by 4 (excluding the two trailing zeros). Therefore, only the year 2000 (20/4 = 5) meets the leap year criteria.
* How to calculate lunar leap years
To calculate a lunar leap year, divide the current year by 19. If the remainder is a number in the series 0,3,6,9,11,14,17, it's a leap year in the lunar calendar.
Here, Mytour has provided quite comprehensive guidance for readers on whether 2017 is a leap year and how to calculate lunar leap years correctly to avoid confusion with the Gregorian leap year calculation method. Knowing whether 2017 is a leap year helps people avoid uncertainty about whether this leap year adjustment is incorrect and affects the Lunar New Year in 2018. Also, knowing whether 2017 is a leap year helps you easily organize time, participate in ancestral worship rituals, festivals, and other activities based on the lunar calendar.
For computer users, errors in date and time are entirely possible. When encountering this issue, adjust the time on your computer by 24 hours to organize your work and studies effectively.
We hope Mytour's insights into whether 2017 is a leap year have been helpful to our readers.
