How Many Days in a Month

Learn how many days are in each month with our complete calendar guide. Months have either 28, 29, 30, or 31 days depending on the month and whether it's a leap year.

Quick Reference

• 31 days: Jan, Mar, May, Jul, Aug, Oct, Dec
• 30 days: Apr, Jun, Sep, Nov
• 28/29 days: February (leap year)

Days in Each Month - Complete Calendar

Month	Days	Leap Year	Season
January	31	31	Winter
February	28	29	Winter
March	31	31	Spring
April	30	30	Spring
May	31	31	Spring
June	30	30	Summer
July	31	31	Summer
August	31	31	Summer
September	30	30	Fall
October	31	31	Fall
November	30	30	Fall
December	31	31	Winter

Memory Tricks & Rhymes

Knuckle Method

Make fists and count knuckles/valleys. Knuckles = 31 days, valleys = 30 days (except February).

Classic Rhyme

"Thirty days hath September, April, June, and November. All the rest have thirty-one, except February alone."

Leap Year Explained

When is a Leap Year?

Every 4 years (2024, 2028, 2032...)
Exception: Century years must be divisible by 400
2000 was a leap year, but 1900 was not
February gets an extra day (29 instead of 28)

Month Categories

31 Days (7 months)

January, March, May, July, August, October, December

30 Days (4 months)

April, June, September, November

28/29 Days (1 month)

February (29 in leap years)

Calendar Facts & Statistics

Average Month:
30.44 days

Total Year:
365 days (366 leap)

Shortest Month:
February (28 days)

Most Common:
31 days (7 months)

Related Time Calculations

About Days in a Month

Understanding how many days are in each month is essential for planning, scheduling, and calendar calculations. The Gregorian calendar we use today has months with varying lengths based on historical and astronomical reasons.

Historical Background:

Originally, the Roman calendar had 10 months
January and February were added later
Julius Caesar reformed the calendar in 46 BC
Pope Gregory XIII refined it further in 1582
February's length varies due to leap year adjustments