How many months have 28 days? | Lunar/Solar Calendar

How many months have 28 days?

How many months have 28 days? There are 12 months that contain 28 days. Have you ever wondered “how many months have 28 days?” I have always found this very interesting and like to collect data about it. If you ask Google, you will get the answer “all 12 months of the year” (which is false; May has 31 days), if you ask your friends or search engines like Bing or DuckDuckGo, you will mostly get the answer “there are twelve months in a year”.

How to define days of a month?

Well, actually it depends on how you define a month. There are at least three ways to define a month: the lunar calendar, the solar calendar, and the weekend calendar.

Month’s days in Weekend Calendar

The weekend calendar is the shortest because every month has exactly 4 weeks (Monday through Friday). The weekend calendar has 4 weeks so every month has exactly 28 days.

Month’s days in Lunar Calendar

All lunar months have 28 days, except the 3rd month of leap years which has 29 days. The lunar year consists of 354 or 355 days and it repeats itself every 19 years; this is why we add an extra day (a leap day) every 4th year. There are 12.37 lunar cycles in a solar year, which means that a lunar month is about 29.53 days long. However, there are approximately 12.37*12 = 149 moons in a 19-year cycle so you get an average of about 29 and a half days per month. The only exception is the 3rd month (March) which has only 28 days if it’s not a leap year, but 29 days if it is.

Month’s days in Solar Calendar

All solar months have 31 days except for February which has only 28 in non-leap years and 29 in leap years.

There are 12 months in which 28 days can be possible, not counting February during a leap year and not including March in a non-leap year.

March, April, August, September, November, and December are the months that can have 28 days during a non-leap year.

Days of February in Leap & Non-Leap Year

February is the only month that has 28 days during leap years.  So there is 12 months total that has 28 days with February being the only month that has 28 days during a leap year.  March, April, August, September, November, and December are the 12 months (excluding February during a leap year) that can have 28 days in a non-leap year. So, only February is 29 during a leap year and 28 a non-leap year.

Leap years occur exactly once every 4th year (except for centurial years not divisible by 400: that is, the years 1700, 1800, and 1900). So there are 12 months that can have 28 days (2 of them being in a leap year, February and March)

When you google you will get “months have 28 days”. First paragraph from google: There are 12 months that have 28 days, not counting February in a leap year and March in a nonleap year. The twelve-month that can have 28 days in a non-leap year are  March,  April,  August,  September,  November,  and  December. And February is the only month that can have 28 days in a leap year.