Why does February only have 28 days?
- 4,396,318 Views
- 1,053 Questions Answered
- Best of Web
In around 45 B.C., Julius Caesar commissioned an expert to put aside the lunar origins of the Roman calendar and make it sun-based, like the Egyptian one. Caesar added 10 days to the calendar year and an extra day in February every four years.
The Gregorian calendar, our modern calendar, was proclaimed in 1582 by Pope Gregory XIII as a reform of the Julian calendar.
Watch these recommended TED-Ed Lessons:
The Leap Year explained
Every four years, we gain an extra calendar day. But why? Neil deGrasse Tyson explains the science behind the leap year.
What causes the phases of the moon?
What causes the phases of the moon? The common incorrect answer is the shadow of the Earth. The phases of the moon are actually just a result of our perception of the moon's half-illuminated surface. When the moon does pass through Earth's shadow the result is a lunar eclipse. This can be spectacular as the moon turns a deep shade of red.
A glimpse of teenage life in ancient Rome
Welcome to the world of Lucius Popidius Secundus, a 17-year old living in Rome in 73 AD. His life is a typical one of arranged marriages, coming-of-age festivals, and communal baths. Take a look at this exquisitely detailed lesson on life of a typical Roman teenager two thousand years ago.
The great conspiracy against Julius Caesar
On March 15th, 44 BCE, Roman dictator Julius Caesar was assassinated by a group of about 60 of his own senators. Why did these self-titled Liberators want him dead? And why did Brutus, whose own life had been saved by Caesar, join in the plot? Kathryn Tempest investigates the personal and political assassination of Julius Caesar.
Create and share a new lesson based on this one.
More from Inventions that Shape History
lesson duration 05:36