Calendar Trivia

I can't believe I've gone through so many years of life without knowing this. The following bit of calendar trivia has recently come to my attention.

In any calendar year, certain months are "partners" and begin on the same day of the week. Hence, all the days in those two months fall on the same days of the week. Pull out a calendar and take a look at the following:

• April & July
• September & December
• March & November

None of these are affected by leap year, so they will always be true! Of course, in non-leap years, February also matches March & November.