Calendars by Country 2025

The World Population Review stated that most countries use the Gregorian calendar. The exception to this is Ethiopia, Nepal, Afghanistan and Iran. The Gregorian calendar is often referred to as the New Style calendar. This is a solar dating system that was proclaimed the official dating system by Pope Gregory XIII in 1582 as a reformation of the previously adopted Julian calendar.

The Difference in The Gregorian and Julian Calendars

The main difference between the accepted Gregorian and Julian calendars is that there is no leap year on the century year unless it is divisible by 400. This leads to a more precise dating system, offering superior date keeping to the Julian variety. The Julian calendar was originally introduced by Julius Caesar to the ancient Roman Republic. It remained the main calendar throughout Europe for more than 1,600 years.

Why The Gregorian Calendar Wasn’t Accepted Right Away

While the Gregorian Calendar was launched as a way to keep a more accurate solar dating system, some protestant countries did not want to adopt this calendar at first because they felt it was a Catholic intrusion based on the fact that it was a pope initiative. However, it was eventually accepted by most countries due to its close adherence to solar rotations. In modern times, the Gregorian calendar is considered the go-to date keeper.

The Gregorian Calendar Saved the Seasons

It takes just slightly more than 365 days for the Earth to make a full rotation around the sun. In fact, it actually takes 365.24219 days. This creates a problem when creating a calendar as any calendar with 365 days precisely will eventually get out of whack. Thankfully, through the years, the Gregorian variety changed the length of their yearly calendar to 365.2425, with changes made possible by alterations with the way leap year was initiated. This puts the length of the year per calendar date closer to the real solar year. Not perfect, but closer than before. It in essence, saved the seasons by making this important change. Otherwise, the months would have eventually been off kilter to the point of not being seasonally appropriate.

The Importance of Calendars

Calendars are vital tools in terms of dating significant events and establishing time periods. Without a consistent calendar that is adopted by most populations, telling time or highlighting significance dates or events can be confusing. Thankfully, our modern calendar keeps the world operating succinctly and orderly.