How many days in a month
| Month | Days | Leap year |
|---|---|---|
| January | 31 | 31 |
| February | 28 | 29 |
| March | 31 | 31 |
| April | 30 | 30 |
| May | 31 | 31 |
| June | 30 | 30 |
| July | 31 | 31 |
| August | 31 | 31 |
| September | 30 | 30 |
| October | 31 | 31 |
| November | 30 | 30 |
| December | 31 | 31 |
The old rhyme covers it: thirty days hath September, April, June and November; all the rest have thirty-one, excepting February alone, which has twenty-eight days clear and twenty-nine in each leap year. The knuckle method works too: count across your knuckles and the gaps, and every knuckle month has 31 days.
Seven months have 31 days, four have 30, and February has 28 or 29. February 2026 has 28 days and 20 weekdays, starting on a Sunday and ending on a Saturday.
How to find days in a month
The weekday count is the practically useful figure and it varies more than the day count does. A 31-day month can hold 21, 22 or 23 weekdays depending on which day it starts, and that three-day swing is enough to move a monthly capacity or billing figure noticeably. A 28-day February always holds exactly 20, which makes it the only predictable month of the year. 28 days is four whole weeks, so every weekday occurs exactly four times and none of them can occur five. Every other length leaves a remainder that has to land somewhere: a 30-day month has two weekdays appearing five times and holds 20, 21 or 22 of them; a 31-day month has three and holds 21, 22 or 23. One further oddity of the arrangement is that only two pairs of 31-day months sit next to each other, July with August and December with January, which is why those are the stretches where a fixed 30-day cycle drifts furthest from the calendar.
Questions
Twenty-eight, or twenty-nine in a leap year.
January, March, May, July, August, October and December.
Between 20 and 23. A 28-day February always has exactly 20, because 28 days is four complete weeks.
July and August, and December and January. They are the only two consecutive pairs.
Any year divisible by four, except centuries not divisible by 400. So 2000 was and 1900 was not.
A legacy of the Roman calendar, which had ten months and treated winter as unnumbered time.
Because the weekday count does. A 23-weekday month holds three more working days than a 28-day February; a 15 per cent difference between two things both called a month.