The months of the year
Twelve months, 365 or 366 days. Seven months have 31 days, four have 30, and February has 28 — or 29 in a leap year. The table gives each month's number, standard abbreviation, length and the origin of its English name.
Months with 31 days
7
Jan, Mar, May, Jul, Aug, Oct, Dec
Months with 30 days
4
Apr, Jun, Sep, Nov
February 2026
28 days
2026 is a common year
Days this year
365
2026
| # | Month | Abbr. | Days | Name origin |
|---|---|---|---|---|
| 01 | January | Jan | 31 | Janus, Roman god of doorways and beginnings |
| 02 | February | Feb | 28 / 29 | Februa, the Roman purification festival |
| 03 | March | Mar | 31 | Mars, Roman god of war — once the first month |
| 04 | April | Apr | 30 | Latin Aprilis, origin uncertain |
| 05 | May | May | 31 | Maia, Roman goddess of growth |
| 06 | June | Jun | 30 | Juno, Roman goddess of marriage |
| 07 | July | Jul | 31 | Julius Caesar (previously Quintilis, "fifth") |
| 08 | August | Aug | 31 | Emperor Augustus (previously Sextilis, "sixth") |
| 09 | September | Sep | 30 | Latin septem, "seven" — seventh in the old calendar |
| 10 | October | Oct | 31 | Latin octo, "eight" |
| 11 | November | Nov | 30 | Latin novem, "nine" |
| 12 | December | Dec | 31 | Latin decem, "ten" |
Why the names don't match the numbers
September, October, November and December literally mean seventh, eighth, ninth and tenth — yet they are the ninth through twelfth months. The early Roman calendar started its year in March, so the numbering originally fit. When the year's start moved to January, the months kept their names while shifting two positions. July and August carry the other visible history: they were renamed for Julius Caesar and the emperor Augustus, replacing the plain numerals Quintilis (fifth) and Sextilis (sixth).
February is short because the Roman calendar treated it as the year's final, unlucky purification month and left it with the leftover days. It later became the natural place to insert the leap day, which it still holds today.
Frequently asked questions
What are the 12 months of the year in order?
January, February, March, April, May, June, July, August, September, October, November, December. In numeric date formats they are written 01 through 12, so ISO 8601 dates read year-month-day: for example, 2026-08-02 is 2 August 2026.
Which months have 31 days?
Seven months have 31 days: January, March, May, July, August, October and December. Four months have 30 days: April, June, September and November. February has 28 days, or 29 in a leap year.
How many days does February have in 2026?
February 2026 has 28 days, because 2026 is not a leap year. February gains its 29th day only in leap years — roughly every four years, with an exception for most century years.
Why is September named after seven when it is the ninth month?
The early Roman calendar began the year in March, which made September the seventh month (septem = seven), October the eighth, November the ninth and December the tenth. When January and February became the start of the year, every one of those months shifted two places — but the names stayed.
How can I remember which months have 31 days?
Two classic tricks: the rhyme "Thirty days hath September, April, June and November", and the knuckle method — count the months across the knuckles of a closed fist, with each knuckle a 31-day month and each valley a shorter one; July and August land on the knuckles of two hands in a row, which is why two 31-day months sit side by side.
What are the standard month abbreviations?
The usual three-letter forms are Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov and Dec. May is already three letters, and September is sometimes written Sept in running text — but data formats and logs almost always use the strict three-letter set.