Prompt Cast
The Evolution of Calendars: From Romulus to Pope Gregory XIII
TLDR The ancient Roman calendar, created by Romulus, had 10 months and only 304 days, but was later modified by Pompilius to have 12 months and 354 days. Julius Caesar introduced the Julian calendar, which had 29 days in February and a leap year every four years, making it the most accurate solar calendar at the time. Pope Gregory XIII implemented the Gregorian calendar in 1582, which adjusted the leap year rule and corrected the calendar by jumping ahead 10 days.
Timestamped Summary
00:00
The Julian and Gregorian calendars are the calendars we use today, with the Gregorian calendar being a modification of the Julian calendar made by Pope Gregory XIII in 1582.
01:54
The ancient Roman calendar, created by Romulus in 753 BCE, had 10 months and only 304 days, but was later modified by Pompilius to have 12 months and 354 days, with the addition of a leap month every few years.
03:43
Julius Caesar introduced the Julian calendar, which had 29 days in February and a leap year every four years, making it the most accurate solar calendar at the time.
05:22
The Julian calendar, with its assumption of 365.25 days in a year, started to cause problems over the centuries, leading to a need for calendar reform, which resulted in the creation of the Gregorian calendar with its rule for leap years.
07:02
In 1582, Pope Gregory XIII implemented the new leap year change and adjusted the calendar by jumping ahead 10 days, but not all countries immediately adopted the Gregorian calendar, with some waiting several centuries to make the change.
08:45
Sweden initially attempted to transition to the Gregorian calendar gradually over 40 years, but due to poor management, they ended up going back to the Julian calendar before eventually making the full switch in 1753.
10:30
The current error in the Gregorian calendar leads to a drift of about one day every 4,000 years, but a proposed addition to the leap year rule would bring the error down to one day per 20,000 years.
