The term "corresponding months" refers to months that begin on the same day of the week within a particular year. The only corresponding months in both common years and leap years are September and December. During common years, January and October; February, March and November; and April and July also correspond. In a leap year, January, April and July; March and November; and February and August are corresponding months.
More about calendar days:
- December always ends on the same day of the week on which April ended that year.
- In years when there is a Friday the 13th during September, there will always be one in December as well.
- Seven months have a length of 31 days. Four are 30 days long, and February is 28 days long during common years and 29 days in leap years.
