The civil calendar is the calendar, or possibly one of several calendars, used within a country for civil, official, or administrative purposes. The civil calendar is almost always used for general purposes by people and private organizations.
The most widespread civil calendar and de facto international standard is the Gregorian calendar. Although that calendar is associated with the Catholic Church and the papacy, it has been adopted, as a matter of convenience, by many secular and non-Christian countries although some countries use other calendars.
Civil calendars worldwide
168 of the world's countries use the Gregorian calendar as their sole civil calendar as of 2021.
Five countries have not adopted the Gregorian calendar: Afghanistan and Iran (which use the Solar Hijri calendar), Ethiopia and Eritrea (the Ethiopian calendar), and Nepal (Vikram Samvat and Nepal Sambat).
Eighteen countries use another calendar alongside the Gregorian calendar: Bangladesh (Bengali calendar), India (Indian national calendar), Israel (Hebrew calendar), Myanmar (Burmese calendar), Egypt (Lunar Hijri calendar and Coptic calendar), Algeria, Iraq, Jordan, Libya, Mauritania, Morocco, Oman, Pakistan, Saudi Arabia, Somalia, Tunisia, the United Arab Emirates, and Yemen (Lunar Hijri calendar).