How Many Days Are in a Month? 28, 29, 30 or 31 Days Explained

Days in Month Calculator

Not every month has the same number of days. Some months have 30 days, others have 31 days, while February normally has 28 days—or 29 days during a leap year.

A Days in Month Calculator makes it easy to select a month and year and instantly find the correct number of days.

This can be useful for scheduling, financial calculations, work planning, travel, deadlines, subscriptions, school calendars, and many other everyday situations.

For official information about calendar months and leap years, see the U.S. Naval Observatory’s calendar reference.

How Many Days Are in Each Month?

The Gregorian calendar has 12 months and normally 365 days.

Here is the standard breakdown:

MonthDays
January31
February28 or 29
March31
April30
May31
June30
July31
August31
September30
October31
November30
December31

Most years contain:

365 days

A leap year contains:

366 days

The extra day is added to February.

Why Does February Have 28 or 29 Days?

February normally contains:

28 days

During a leap year, February contains:

29 days

That extra day helps keep the calendar aligned with Earth’s journey around the Sun.

Therefore:

February 2025 = 28 days

but:

February 2028 = 29 days

How Do You Know If a Year Is a Leap Year?

A useful rule is:

1. If the year is divisible by 4, it is usually a leap year.

2. If it is divisible by 100, it is normally not a leap year.

3. However, if it is divisible by 400, it is a leap year.

Examples:

2024 ÷ 4 → Leap Year ✅

2026 → Not a Leap Year ❌

1900 → Not a Leap Year ❌

2000 → Leap Year ✅

This special rule keeps our calendar more accurately aligned with the solar year.

The 30-Day Months

Four months contain exactly 30 days:

April

June

September

November

A familiar memory rhyme begins:

“Thirty days hath September, April, June and November…”

This makes the 30-day months easier to remember.

The 31-Day Months

Seven months contain 31 days:

January

March

May

July

August

October

December

That means most months of the year actually contain 31 days.

Quick Month Examples

Example 1 — September

Select:

Month: September

The result is:

30 DAYS

Example 2 — January

Select:

Month: January

The result is:

31 DAYS

Example 3 — February 2026

Select:

Month: February

Year: 2026

Since 2026 is not a leap year:

28 DAYS

Example 4 — February 2028

Select:

Month: February

Year: 2028

Because 2028 is a leap year:

29 DAYS

Why Use a Days in Month Calculator?

Remembering whether a month has 30 or 31 days is usually easy, but February makes the calculation dependent on the year.

A calculator removes the guesswork.

Simply select:

Month + Year → Number of Days

The calculator automatically determines whether February should contain 28 or 29 days.

Where Is This Calculator Useful?

📅 Scheduling — determine exactly how many calendar days are available.

💼 Work planning — organize monthly schedules and projects.

💰 Budgeting — understand the length of monthly financial periods.

✈️ Travel — plan trips around particular months.

🎓 School calendars — organize study periods and activities.

🏠 Home planning — schedule monthly tasks and projects.

📦 Subscriptions & billing — understand different month lengths.

🎂 Events — plan birthdays, anniversaries and special occasions.

How to Use the Days in Month Calculator

Using the LivingToolsGuide calculator is simple.

Step 1: Select the month.

Step 2: Enter or select the year.

Step 3: Click Calculate.

Step 4: See the exact number of days in that month.

For February, the calculator automatically checks whether the selected year is a leap year.

Calculate the Days in Any Month

Need to know whether a particular month has 28, 29, 30 or 31 days?

Use our Days in Month Calculator and get the answer instantly.

👉 Use the Days in Month Calculator