Who decided how many days there should be in each month?

Question

And why does October have 31, Nov 30 and so on

Answer 1

Short extract, see link for rest

Originally Romans had ten months in the year of either 30 or 31 days. The winter period seems to have been without formal months and the year began in the Spring with March as winter ended and crops were planted. The ten month year is still recalled in the names of some of our months - September, October, November, and December come from Latin words for seven, eight, nine and ten.

Around 715BC the twelve month calendar was introduced, based on the phases of the Moon. It takes on average 29.5 days between one new moon and the next and so a twelve-month lunar year lasts 354 days but an extra day was added because even numbers were unlucky. The twelve months had between 28 and 31 days in each to make the year last 355 days. February was the shortest month with 28 days and every other year a whole extra month - called Mercedonius which alternated between 22 days and 23 days - was inserted after the 23rd day of February to try to keep the calendar in line with the solar year of approximately 365 days. At the end of Mercedonius the remaining five days of February were taken, so Mercedonius was followed by the 24th of February. But the arithmetic did not quite work - the system gives an average duration for the year of 366.25 days - and the calendar slowly drifted away from the seasons once more. Inserting an extra period to correct the calendar is called an intercalation.

Answer 2

That was decided in about the year 15 AD. Before the time of Julius Caesar the calendar had ten months. The first six were given names of minor Roman Gods. The last four were simply named Septum, octo, novem, decem. In Latin that means seven, eight, nine, ten.
When Julius died in 14 BC, the senate decided to name a month in his honor. To further honor him they wanted the month to be a nice warm summer month, so it was inserted after June.
In 44 AD Augustus died. They gave him a warm summer month also. Both were honored by having the maximum 31 days
In each case the number of days in each month had to be juggled around to make the days come out right.
Julius himself said that he noticed that the seasons were shifting, so he computed that the orbit of the sun does not match the rotation of the earth. In order to bring things back into order, he removed 28 days from the calendar, and directed that a year will be computed to be 365 days and 6 hours.
Actually it's 365 days 5 hours 28 minutes, and 26 seconds, Julius had it close enough.
So a direct answer to your question is- - - Julius Caesar and the Roman Senate did most of the calculating, with adjusting by the Senate at the time of Julius' departure.

Answer 3

Julius Ceasar -- we basically use the "Julian" calendar he implemented during the Roman Empire.
We've made slight modifications to keep the calendar year in line with the astronomical year, and we've re-arranged the order of some of the months, but what old Julius came up with 2,000 years ago works pretty well, so we only had to tweak it instead of replace it. His original calendar was off from the astronomical year by a good 14 days by the mid-1500s, and when changes were made to get it back in-line then some countries refused to go along, which was funny...you could be in one country and it would be Jan. 10th, and be in another country and it would be Dec. 26th. Everybody finally came around :)

Answer 4

One of Julius Caesar's mates. This was after many centuries of experimentation, and it took quite a few more to get February to work.

Answer 5

Days In Each Month

Answer 6

no idea however you must remember there are 28 days in febuary minus leep year.

Answer 7

I believe it was the Romans.

Answer 8

its a roman calendar. ask them.

Answer 9

a mexican man from cuba