Number of days in the year in the Gregorian calendar
The number of days in the solar year is approximately 365 days and a quarter of a day, but the Gregorian calendar depends on the existence of 365 days in the regular Gregorian year, then one day is added to the calendar every 4 years to compensate for the difference in days, so that the number of days becomes 366 days, and the year in which the number of days increases by one day is known as a leap year.
Number of days in the month in the Gregorian calendar
The number of days in the month in the Gregorian calendar is 31 days for each of the first month, the third month, the fifth month, the seventh month, the eighth month, the tenth month, and the twelfth month, while the fourth month, the sixth month, the ninth month, and the eleventh month; the number of days in them is 30 days, and the number of days in the second month is 28 days in a regular year, and becomes 29 days in a leap year.
Different names for the Gregorian calendar
There are several different names given to the solar Gregorian calendar, including: the Gregorian calendar, named after Pope Gregory XIII, the Western calendar, because the West uses it while the countries of the Islamic world relied on the Arab Hijri calendar, and the Christian calendar, the Christian calendar, or the Frankish calendar.