# Why is the number of days in each month not the same for ease of calculation?

We all know that a year has 12 months, equivalent to 365 days. So how many days should be reasonable in each month?

Later, when people compiled the calendar, it remained unchanged.

If calculated according to 30 days, a year should have 7 months and 30 days, 5 months and 31 days. But now the number of days in each month is not calculated that way. Why is that?

According to records from a long time ago, there was a Roman Emperor who thought that February was not good, so he ordered one day of February to be reduced and brought in July.

Later, a Roman Emperor said he was born in August, that month must also be added a day. So one more day is taken from February. So, February is only 28 days.

Later, when people compiled the solar calendar, it remained unchanged. So the current solar calendar has 7 months and 31 days; that is 1, 3, 5, 7, 8, 10, 12 and 4 months 30 days; that is April, June, September, 11. Particularly, February has only 28 days or 29 days .