solar calendar

Why are the number of days in each month not the same for easy calculation?
We all know that a year has 12 months, which is 365 days. So how many days per month should be reasonable?
Why is there a 29/2 leap date?
Why is there a leap day? What is a leap year? What is leap month? Let's find out what a leap day, a leap month and a leap year are.
Why is the world in 2018 but this strange country is still 2011?
The positive calendar that we use to calculate the time is called the Gregorian calendar. It was first created in 1582 by Pope Gregory XIII.
Why is the solar calendar in February only 28 or 29 days?
The original Roman calendar was issued by Romulus, the first emperor of Rome. His calendar is based on the Moon's cycle.