Such an odd month
 

Not only does February have less days than other months, but this February is truly unusual. There are 4 of each day of the week. According to my granddaughter, this only happens about once every 500 years.

:1rotfl: My observation all the days of the week end in y how odd

I think grand daughter is pulling your chain. :coolsmiley:

Actually it's once every 6 years or...
 

twice every 11 years that it has exactly 4 weeks...easy enough to substantiate...google it...

Whenever a month has 28 days, there will always be exactly 4 of each day of the week. Leap Year is the only time when February does not have exactly 4 of each day of the week.

If you do not believe me, look at a February calendar for any year that is not a lap year.

Damned Common Core and New Math.

Take a good look at a calendar. February has to start on a Sunday for every day to appear four times in the month. This does not happen often, certainly not in any of our lifetimes. Leap year is irrelevant.

OK, explain last year

http://www.calendarbar.org/calendarb...calendar-3.gif

In a 7 day period, each day of the week happens exactly once.
In a 14 day period, each day of the week happens exactly twice.
In a 21 day period, each day of the week happens exactly three times.
In a 28 day period, each day of the week happens exactly four times.

In a 29 day period , i.e. Februarys in leap years, 6 days of the week happen exactly 4 times and one day of the week happens 5 times. (4x6 +1x5 = 29).

For what it's worth, February started on a Sunday in 2009.

Ok, I think the OP means 4 weeks as in 4 lines and no partial lines on a printed calendar unlike the 2014 one above which has 5 printed (some partial) lines. The term the OP was missing in the post is "perfect month"

Thus you must start, using the traditional American way of presenting a calendar, with Feb 1st being a Sunday for this year to be a perfect month. As there are 7 days in a week, one of every seven years would seem to have Feb 1 be a Sunday. If there were no leap years, then the correct answer would be, 1 in 7 years the Feb calendar consists of just 4 lines. However we have leap year. Every leap year fails as they obviously have 29 days. And you need to do a correction not just because every 4th year automatically fails but the leap year makes the next year's assignment of Feb 1 advance by one day.

In a normal pair of years which day of the week a particular date falls upon goes up by one. Thus in 2013 Feb 1 was a Fri, in 2014 it was a Sat and in 2015 it is a Sun, in 2016 it will be a Mon even though 2016 is a leap year we don't get the leap day until after Feb 1. Then in 2017 it will be a Wed. 2018 a Thurs, 2019 a Fri, 2020 a Sat. Here is gets interesting as 2021 it should be a Sunday again creating a perfect month but NO, it is a Mon as we have a leap day in 2020. The next perfect month will be .. c'mon draw it out for yourself now that you see the pattern (every 6 or 11 years by the way)

I feel sorry for February having only 28 days. Why don't they take one day from January, one day from March and give those two days to February? So all three months would have exactly 30 days.

Answer: There are birthdays on the 31 and they would get messed up.

What AG said. Not really rocket science if you think about it a little. :)