Post by ꧂༄ᴺᵉᵖ᭄✿ on Mar 22, 2024 18:10:50 GMT
Most people know that a single day is about 24 hours long and that there are 365 days in a year.
"But it actually takes Earth 365.242190 days to orbit the sun," says Jackie Faherty, an astronomer at the American Museum of Natural History in New York.
"And that .242190 days to go around the sun is the entire reason why we have a leap year," she explains.
"Centuries ago, people kept track of the sun's position — such as for a solstice or the longest day of the year — to know when to do things, like plant and harvest. Over time," she says, "the need grew for a centralized calendar system."
The Hebrew, Chinese and Buddhist calendars, among others, have long contained entire leap months. The West is no stranger to leap years either.
The Julian Calendar, which Julius Caesar introduced in 45 BC, included an extra day every 4th year. He borrowed the idea from the Egyptians, though his math wasn't exactly correct. Caesar overestimated the solar year by about 11 minutes, leading to an overcorrection by about eight days each millennium. That explains why Easter, for example, fell further and further away from the spring equinox over time.
Pope Gregory XIII sought to address that problem in the 16th Century with the Gregorian Calendar, which adds leap days in years divisible by four, unless the year is also divisible by 100. To make matters even more confusing, a leap day is still added in years divisible by 400.
Why add the extra day in February? The Romans considered it to be an unlucky month. On top of that, they were deeply suspicious of odd numbers. Because February only had 28 days to begin with, they 'just shoved it into February', though leap day used to be on the 24th.
On the one hand, you don't want a calendar that makes it so complicated to know how many days it's going to be from one year to the next. But on the other hand, you want to make sure that holidays stay in their proper seasons, especially if your holidays are related to things like agriculture, harvest holidays and whatnot.
"But it actually takes Earth 365.242190 days to orbit the sun," says Jackie Faherty, an astronomer at the American Museum of Natural History in New York.
"And that .242190 days to go around the sun is the entire reason why we have a leap year," she explains.
"Centuries ago, people kept track of the sun's position — such as for a solstice or the longest day of the year — to know when to do things, like plant and harvest. Over time," she says, "the need grew for a centralized calendar system."
The Hebrew, Chinese and Buddhist calendars, among others, have long contained entire leap months. The West is no stranger to leap years either.
The Julian Calendar, which Julius Caesar introduced in 45 BC, included an extra day every 4th year. He borrowed the idea from the Egyptians, though his math wasn't exactly correct. Caesar overestimated the solar year by about 11 minutes, leading to an overcorrection by about eight days each millennium. That explains why Easter, for example, fell further and further away from the spring equinox over time.
Pope Gregory XIII sought to address that problem in the 16th Century with the Gregorian Calendar, which adds leap days in years divisible by four, unless the year is also divisible by 100. To make matters even more confusing, a leap day is still added in years divisible by 400.
Why add the extra day in February? The Romans considered it to be an unlucky month. On top of that, they were deeply suspicious of odd numbers. Because February only had 28 days to begin with, they 'just shoved it into February', though leap day used to be on the 24th.
On the one hand, you don't want a calendar that makes it so complicated to know how many days it's going to be from one year to the next. But on the other hand, you want to make sure that holidays stay in their proper seasons, especially if your holidays are related to things like agriculture, harvest holidays and whatnot.
Smile, make someone's day. Makes your day. 
