This is a solar calendar indicates the position of the Earth in respect to the SunThe Gregorian calendar is typical of the Christian era and presents the death of Jesus Christ as year zero or startIt is present in the vast majority of European countries.

Julian Calendar

Julius Caesar changed the Roman calendar in the first century after Christ (AD) to coincide with the four seasons. Thus was born the Julian calendar.

Later, following the death of Julius Caesar, Augustus, which will alter the schedule eliminating the leap year which had been introduced in the Julian calendar. Also introduced a month in his honor (August), which had 31 days as of Julius Caesar (July).

History

In 1582 Pope Gregory XIII created the Gregorian calendar in which made an adjustment dates to coincide exactly with the four seasons since with the passage of time there had been mismatches. In addition, overcame three leap years every 400 years.

This schedule was adopted immediately by Spain and Italy, which followed France. The Protestant religion of England would take it in the seventeenth century and Russia and Turkey in the Twentieth Century.

How it works

In the Gregorian calendar, there are three fundamental concepts:

·  It is the time it takes to turn the Earth on its axis 360 º. According to the TAI (International Atomic Time) are 86,400 seconds.

·  Week: consists of 7 days.

·  Month: period of 28, 29, 30 0 31 days.

The year consists of 12 months of 30 days each and a half, resulting in 365 days. It is divided into seven months, 31 days, 30 days and 5 1 month of 28 days, although it may be 29 if leap. There are several types of years:

·  Common: it has 365 days' duration

·  Bisiesto: it produces each year a multiple of 4 and has 366 daysThe month of February is the one that is affected by this year from 28 to 29 days.

·  The year is secular that year with the ending a century such as the year 100, 500 or 2000. Only if they are leap multiples of 400.

From the months

The names of the months of this calendar have their origin in Julian. Their names and backgrounds are as follows: