Twelve month of the year
One year is in today's Grigorian calender subdivided into 12 month. You can choose between 28, 29, 30 or 31 whole month. Every month has either 28, 30 or 31 dates during a joint year that has 365 dates. On 29 February, during the four-year cycle of interleap years, we are adding an additional (leap day), making interleap years 366 in number.
The aim is to reconcile our present schedule with the sun year and the astronomic season, which is characterized by the equinox and equinox. There are 12 month of the Grigorian calendar: They were created to indicate the period of the year and to divide it into short intervals on the basis of the moon's circularity.
Month is even a term that derives from themoon. To our knowledge, for the first in Mesopotamia between the years 500 BC and 400 BC month were used to determine the amount of month of nature associated with the month of the moon, the synod month, which is the amount of elapsed moon to pass through all moon-phase.
What are 28, 29, 30 or 31 of them? There are 4 month in the Bregorian calender, which are 30 and 7 month, which are 31 day long. The only month that is 28 in joint years and 29 in intercalary years is February. Both our actual Grigorian calender and its forerunner, the Julian calender, have 12 month.
There were also 12 month old calendars in Rome, but only 10 of the month had a name. September, October, November and December were postponed by the additions from January and February to later in the year, so that they no longer reflect the initial significance of their name. Originally used in the Romans, their name means the seventh, eight, nineth and tithest month.
You can find many diaries that still use month to split the year. Among them are the Muslim and Hebrew and Hindu calender. Even though the Grigorian calender is the most frequently used calender today, other calender are still used to compute certain public and yearly celebrations according to the Grigorian calender.
Included in the old calender: months: The Mercedonius - an incidental month after February, which was used to re-align the Rome calender. We use Leap Day today for this purpose. The Sextilis - re-named August in honour of the Emperor Augustus in 8 B.C..