Let us first know what is the Hijri calendar or date

Hijri calendar or lunar calendar; is a calendar followed by Muslims determine the lunar months, which depends on the moon cycle, this calendar needs all Muslims because it identifies the most important Islamic religious events such as the beginning of the holy month of Ramadan, Eid al-Fitr and Eid al-Adha and many important religious events for Muslims And sometimes we need to convert the date from Hijri to Gregorian to be used in official letters, especially if you are a resident of Saudi Arabia or Morocco or if you are addressing one of these countries that use Hijri date as a basic date with the use of Gregorian date as well

At the beginning let me show you how the Hijri year is divided and what are the names of the Hijri months What are the Hijri months in Arabic and English?

The Islamic Hijri year consists of 354 days divided into 12 months.

Muharram
Safar
Rabi' al-awwal
Rabi' al-thani
Jumada al-awwal
Jumada al-thani
Rajab
Sha'ban
Ramadan
Shawwal
Dhu al-Qi'dah
Dhu al-Hijjah

1- محرم
2- صفر
3- ربيع الأول
4- ربيع الثاني
5- جمادي الأول
6- جمادي الثاني
7- رجب
8- شعبان
9- رمضان
01- شوال
11- ذو القعدة
21- ذو الحجة

How to convert history from Hijri to AD
You can convert the date from Hijri to Gregorian by doing some accounting operations to know the date of the Hijri day or use Hijri date converter tool , but how to convert the date from Hijri to Gregorian calculations ?! I will show you now, but before doing these complex calculations I found an online tool that converts the date from Hijri to Gregorian through the site with great accuracy you can convert between any two dates at any time and very quickly.

The law of converting the date from Hijri to Gregorian:
Hijri date = (Hijri date + 622) - (Hijri date / 33)

Example if you want to convert from Gregorian Hijri and you in (1440 AH)

So the Gregorian date will become = (1440 + 622) - (1440/33)

Gregorian date = 2018.

The law of conversion from Gregorian to Hijri date:
Hijri date = (Gregorian date - 622) / 0.97
Example if you want to convert from Hijri to Gregorian and you in (2020)
Hijri date is = (2020 - 622) / 0.97
Hijri date = 1441 AH.

Islamic events for 2020
Ramadan: April 24 – May 23, 2020
Eid ul-Fitr: May 24, 2020
Hajj: July 28 – August 1, 2020
Eid ul-Adha: July 31, 2020
Islamic New Year: August 20, 2020 (1442 A.H.*)
Ashura: August 31, 2020
Mawlid an-Nabi (Prophet Muhammad’s birthday): October 29, 2020