Before we start discussing how many months1 have 28 days, we should remember some facts about the Gregorian calendar, which is internationally accepted in the modern world. It will help us to find the right answer to this question. And it is not as obvious as you may think.
The Gregorian calendar
The Gregorian calendar was introduced on February 24, 1582, by the decree of Pope Gregory XIII. The calendar was named in his honor, but it is also known as the Christian (or Western) calendar. It was adopted later by other countries, though it took centuries for some of them.
The new variant was needed because the Julian calendar stated that there was 365.25 days between vernal equinoxes, though this time is eleven minutes shorter. The result of this error equals to approximately three days in four centuries. The Gregorian calendar corrected the mistake and modified the leap years2.
This table shows how many days every month has according to the Gregorian calendar.
Month
Days
January
31
February
28, or 29
March
31
April
30
May
31
June
30
July
31
August
31
September
30
October
31
November
30
December
31
The mean length of the month in the Gregorian calendar is equal to 30.436875 days.
How Many Months Have 28 Days?
According to the table below, only one month (February in a common year) consists of 28 days. But does it mean that all the other eleven months do not have 28 days? A tricky question, isn’t it?
In fact, all the twelve months in every year (including leap years) have 28 days. Of course, almost all of them have also the 29th, the 30th and even the 31st days, but not a single month has less than 28 days. In other words, we may say that 28 days make up only February (except Februaries in leap years), or February is the only month that has no more than 28 days (we have already said about leap years), but every month includes 28 days.
The following video will teach you the simple way to find out how many days every month of a year has:
The month is a time unit used in calendars. The Gregorian calendar consists of twelve months, which have from 28 to 31 days.
The leap year is an uncommon year that contains one additional day (in some calendars – a month) to synchronize the calendar year with the seasonal (or astronomical) year. In the Gregorian calendar, it usually happens once in four years and leap years last 366 days (February has one more day). If a year is evenly divided by 100 and not divided by 400, it is not a leap year. For example, 2000 was a leap year, but 2100 will not be a leap year.