February 29 is a date that is noted once every four years. The reason 2016 is a leap year is astronomical.
February 29 is a date specified once every four years (with a few exceptions, as we will see later) - this is actually the Roman version of the term leap year. The reason for adding this day was astronomical.
A "year" is the amount of time it takes the earth to make one revolution around the sun. The definition of a year is a period of 365 days, and this is reflected in the Gregorian calendar that is currently in use all over the world.
While both definitions are correct, each describes a different type of year. The time it takes for the Earth to go around the Sun once is called a solar year or a tropical year. Astronomers define the tropical year as the period of time between one vernal equinox and the next. The length of this year is 365 days plus approximately five hours, 48 minutes and 45 seconds.
The rest is due to the fact that the length of the day - the time it takes for the earth to rotate once around its axis, does not correspond exactly with the amount of time it takes for the earth to go around the sun.
The length of the day - 24 hours is also not accurate, because the actual time of the earth's revolution around its axis - a sidereal day is 23 hours, 56 minutes and 4 seconds - for a year we get the same almost six hours. 24 hours is the length of time we see the complete circle due to the Earth's upward movement approximately every day.
If we leave the situation uncompensated, we will reach a situation where the calendar goes out of sync with the seasons as we know them, about a full month once every 125 years.
However, the date on which the "lost time" should be returned is not so important, as long as it is taken into account somehow. Of all these balancing options, the easiest is to collect the excess hours and use them all at once. And this is where February 29 comes into play.
Once every four years, since the Julian calendar was introduced by the Romans, an update has been used in the form of adding one day - the leap day that will make the year a leap year, which is added to the shortest month of the year - which in the Roman period was also the last day of it, and it is short because the emperors Julius and Augustus took Each one a day from it so that the month in their name will be 31 days long.
But this was not a simple solution either. While the Romans' plan worked, it actually overcompensated by 11 minutes and 15 seconds per year.
To round back or at least get close to it, the law of adding the day once every four years has one exception - which was introduced into the Gregorian calendar - which was an update to the Julian calendar - the years divisible by 100 are not leap years, unless the year is also divisible by 400. Since the Gregorian calendar was introduced in 1582, the year 1600 was a leap year, 1700, 1800 and 1900 were not leap years and the year 2000 had 29 days in February. Similarly 2100,2200 and 2300 will not be leap years but 2400 will be.
Why is such a year called the leap year?
The term leap year comes from the addition of the leap day. The name Skip Day comes from its influence on the way the days of the year line up with the days of the week. When moving from one normal year to another, the same day of the year will advance one day a week. For example, June 10 fell on a Tuesday in 2014, which was a regular year, and on a Wednesday in 2015. In 2016 this date will fall on a Friday as it skips a Thursday because of February 29th.
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Yaniv
Maybe you could expand on the Hebrew board
very interesting
Yes, there is a simple correction to the civil calendar that, if carried out at the time, would have completely corrected the error of the Julian calendar (see the "Gregorian Calendar" Wikipedia talk page).
Too bad you don't learn. You are allowed.
A wonderful explanation.
What about referring to the Hebrew calendar? Its accuracy?
Thanks