The Hijri and Gregorian calendar New Year, also known as the Gregorian, Western, Christian calendar, is the Hijri and Gregorian calendar, the New Year, which is used civilly in most countries of the world. The author of the counting of years was also believed to be the Armenian monk Denisius the Younger. The Gregorian calendar is named after Pope Gregory XIII, Pope of Rome in the sixteenth century, who modified the system of pressing in the Hijri and Gregorian calendars for the new year to become the current system. The Gregorian year is a solar year, meaning that it represents a complete cycle of the sun in its homes, which is a period of (365,2425) days. Therefore, the Gregorian year has 365 days in a simple year and 366 in a leap year, and it consists of 12 months. The Julian calendar was less accurate, as it considered the solar year to be 365.25 days.

The Gregorian Reformation was initially adopted by the Catholic states in Europe and by their satellite states abroad. Over the next three centuries, Protestant and Eastern Orthodox countries also moved to what they called an "improved Hijri and Gregorian New Year calendar", with Greece becoming the last European country to adopt the Gregorian calendar in 1923. Due to globalization in the twentieth century, the calendar was adopted by most Non-Western countries for civil purposes. The calendar era bears the alternative secular name "general era".