All  

Gregorian

Mosaic with the months of the year, starting with the Roman first month March.

Where do the names of our months come from?

Our lives run on Roman time. Birthdays, wedding anniversaries, and public holidays are regulated by Pope Gregory XIII’s Gregorian Calendar , which is itself a modification of Julius Caesar’s calendar...
Detail of a star chart dating to the Middle Kingdom.

Why Are There 365 Days in a Year? Organizing Dates with an Ancient Egyptian Calendar

The calendar is one of mankind’s most important inventions. Calendars allowed societies to organize time for religious, social, economic, and administrative purposes. The calendar, or rather, two...
Bologna, San Petronio: Meridian of Giandomenico Cassini

Synchronizing Science and Religion? Why We Find Solar Observatories and Astronomical Features in Churches

It is often assumed that science and faith are always at loggerheads with each other. This, however, is a common misconception, as there are numerous instances demonstrating the co-existence and co-...
The Roman Origins of Our Modern Calendar - Influenced by Popes, Generals, Emperors and Gods

The Roman Origins of Our Modern Calendar - Influenced by Popes, Generals, Emperors and Gods

The most widely used calendar around the world today is called the Gregorian calendar. It was introduced by Pope Gregory XIII in the 16th century CE and was a modification of an ancient Roman...
Tzolkin section in the Dresden Codex, starting from the day 1, Manik'.

Sacred Calendars and New Years: Cycles of Time and Ages

The global holiday of a new year symbolizes all we have experienced for the duration of the year, and all our hopes and dreams for the year ahead. Such observances date back over 4,000 years, often...
Pope Gregory XIII, portrait by Lavinia Fontana (Public Domain) A Page from a 1584 version of the Gregorian Calendar.

New Year, Old Calendar: The Origins and Controversy of the Gregorian Calendar

The most commonly used civil calendar today is known as the Gregorian calendar, which is also called the Western calendar, or the Christian calendar. This calendar was named after Pope Gregory XIII,...