How to calculate Easter: formula

2024 Author: Miguel Ramacey | [email protected]. Last modified: 2023-12-17 06:11

Most of the population of our country professes the Christian faith, but most of these people are still wondering why Christmas is always celebrated on the same day, regardless of the year, and His Resurrection occurs on different dates? Strange, isn't it? In fact, the reason for this was the disagreement of the churches, and initially the date of Easter was also fixed.

Dating history

The first Christians were Jews, and they celebrated the Resurrection of Christ on the fourteenth day of the month of Nisan. According to the modern calendar, this period falls on March-April. Already in 325 AD, the Holy Church decided that it would not celebrate Easter with the Jews, and fixed another date for this holiday. It was from that moment that the question arose of how to calculate the date of Easter, because now it has become floating. The first Sunday after the first spring full moon was assigned to the main religious event. The latter also changed and was calculated based on the day of the vernal equinox.

According to this conclusion, the time of the celebration depended on the solar and lunarcalendars and could fall on the period from March 22 to April 25 according to the old style.

Calculation according to the lunar calendar

Before you calculate the day of Easter in the new year on your own, you should remember the main rule on which the calculations of both the Gregorian and Alexandrian Paschals are based: "The Resurrection of the Lord is marked by the first Sunday following the spring full moon." The full moon in spring is considered the first if it comes after the day of the vernal equinox.

How to calculate Easter correctly according to this requirement? First of all, you need to calculate the position of the moon, or rather, the date of the full moon in a particular year. For this, the Metonic cycle is used: full moons are repeated every 19 years. In the first year of our era, the Moon was in position 2, therefore, the calculation of the circle of the Moon will be as follows:

(X-2)/19

With the result obtained, the age of the Moon on the first day of March is already calculated. First, the golden number of the cycle is determined by adding the number 3 to the result of the previous calculation. After that, the age itself is determined:

(11gold number)/30, where 11 is the constant difference between bases and 30 is the number of days of the lunar month.

It is important to consider that you need to get not the result of the calculation itself, but the whole remainder when dividing, it will be the age.

How to calculate Easter next? It is necessary to subtract the result from 30, and then add 14 to the answer. If the date is earlier than the equinox in this way, then you need to count Easter from the nextfull moon. If the date fell on a Sunday, then the Resurrection of Christ will be celebrated on the next Sunday.

Calculation by formula

In the 18th century, the German mathematician Friedrich Gauss proposed to the Church his formula for calculating the celebration of the Bright Holiday.

This principle is based solely on mathematical calculations and determines Easter according to the Gregorian calendar. The formula for how to calculate Orthodox Easter looks similar, only the difference between the old and new calendar, which is 2 weeks, must be added to the result obtained at the very end. So, the actions must be performed in the following sequence:

1. The numerical value of the desired year should be divided by 19, and the whole remainder calculated. He will be first.
2. Then the same year is divided again by 4, and the remainder, called the second, is also calculated.
3. The number of the year is again divided by 7 and the whole remainder is also remembered.
4. The first result is multiplied by 19, 15 is added to it, then everything is divided by 30, and the remainder (fourth) is calculated.
5. The second result is doubled, the third is multiplied by 4, and the fourth is multiplied by 6, after which all the results are added together, and 6 is added to them.
6. The final number is divided by 7, and the resulting remainder determines the date of Easter.

If the end result is less than 9, then the holiday is dated March. The exact date is calculated by adding the number 22 and the remainders 4 and 5.

If the result is greater than 9, thenThe resurrection will be celebrated in April and the exact date is determined by adding the same balances, only with the further calculation of the number 9 from them.

Now, in order to calculate the Orthodox Easter, it remains only to add 13 to the received dates, since the Gregorian and Julian calendars differ by this number of days.

Calculation example

In fact, determining the exact date of the main Christian holiday is not as difficult as it seems at first glance. To make it clearer how to calculate Easter without taking into account the position of celestial bodies, below are the calculations for the date of the Resurrection of Christ in 2018 according to a mathematical formula.

So:

1. The first action is the division of the year 2018/19=106, 21…, which means the whole remainder will be 4.
2. Now 2018/4=504, 5. Whole remainder 2.
3. Next 2018/7=288, 28…. The remainder will then be 2.
4. Now you should determine the fourth remainder - ((419) + 15)/30=3.03, the remainder is 1.
5. Next 22=4, 24=8, 16=6. Now 4 + 8 + 6 + 6=24.
6. Result 24/7=3, 43, remainder 3.
7. 3 + 1=18 - the sum of the balances is less than 9, which means the date is in March.

Thus, we get that the Resurrection of Christ this year will be celebrated on March 26 according to the old style and April 8 according to the new one, since 4 + 22=26.

More calculation options

The easiest way to determine Easter is knowing the exact date of Pancake week, because it is on the fortieth day from its last day that the Holy Resurrection of the Lord is celebrated.

You can also use the Alexandrian Paschalia for this. How to calculate Easter in this way? It is necessary to calculate the value of the full moon, and if it is less than 32, then the full moon will be in March for the first time in spring, and if more - in April. In the latter case, the exact date is determined by a calculation from the result of 31. The formula for this is as follows:

equinox date + ((19(Y / 19) + 15) / 30)

Conclusion

It is not difficult to independently calculate the dates of church holidays, given all the rules. Many nuances that only experienced people understand can confuse an inexperienced person. Difficulties can also arise in calculations, because if at least one value is incorrectly determined, then the final result will be incorrect.

If such calculations seem too complicated, then you can simply use the already prepared results of calculations for subsequent years:

• 2019 – 28.04;
• 2020 – 04/19;
• 2021 – 2.05;
• 2022 – 24.04;
• 2023 – 16.04.

If you wish, you can try to calculate further dates yourself or find them on various resources on the Internet.