How many days a year? The question seems to be simple, because any first-grader knows the answer - 365. And in a leap year - 366. But not everything is so simple. Let's clarify - in what year? In order not to be mistaken with the answer to the question: “How many days are there in a year?”, We must first decide by what calendar we will calculate the duration of the year - according to the lunar, solar or solar-lunar?
Counting time is complex matter. Subjectively, it seems to us that it is either faster or slower, then galloping, or crawling like a turtle. You can’t rely on your feelings. Therefore, people turned to what they considered unshakable: sunrise and sunset, moon phases and stars. Moreover, the stars are closer than the Sun, simply not.
The most obvious time unit was a day. This is nothing but one bright and one dark range of time, or day and night. This was clear even in the deep Paleolithic.
Over time, people became more or less clear what a year is. This is the time between the days when the Sun appears at the same point in the sky. How many days a year? The answer was also found quickly enough. The year was approximately 365 days.
But to consider the length of the year as inconvenient. It was necessary to group the days into another intermediate unit of measurement. Such a unit was found, and it became the lunar month. The natural night lamp was visible to ancient people from anywhere in the world, so from the time of the same Paleolithic people began to count time in accordance with the phases of the moon. Confirmations of this are regularly found by archaeologists.
But here's the bad luck - the duration of the solar year of the month was not divided without a remainder by the duration of the lunar month. Moreover, the lunar month continues for an incomplete number of days. It ranges from 27.5 to 29.5 days. 12 lunar months, or lunar year, are therefore 354 or 355 days. This is 10 or 11 days less than a sunny year!
Nevertheless, for example, in Islam the year is still considered according to the lunar calendar. And for a true Muslim, it is obvious how many days a year is - 354 or 355. The beginning of each year in Islam is floating. The next Islamic New Year falls on 11/05/2013. On this day, the Muslim year 1435 of the Hijra begins. The Muslims took the year 622 as a reference point for the year 622, when, fearing for his life, Muhammad, together with his comrades, fled from Mecca to neighboring Medina.
There is also a lunar-solar calendar. This is, for example, the Jewish calendar. The lunar month is also taken as a basis. The year begins at the spring full moon - Easter - and lasts 12 months, of course, the moon. But to bridge the gap between the lunar and solar years, a whole additional lunar month is periodically added. This happens in leap years. Moreover, the duration of the month is tied to the phases of the moon. A month can only begin on a new moon. So, it turns out, according to the Jewish calendar, a year can be 353, and 354, and 355, and 383, and 384, and 385 days. So how many days a year?
The most widespread, and perhaps the most convenient calendar is the solar one, where the period of revolution of our planet around the sun for a year is taken. And its duration is known to any student. So, according to the solar calendar, how many days are there in a year? 2013 is not a leap year, so it has 365 days. But the previous one, 2012, was a leap year and had a length of 366 days.