How to Calculate Days Between Two Dates (Step-by-Step Guide)

Finding the number of days between two dates is a common need for students, office work, form filling, project planning and personal use.

In this guide, you’ll learn:

• The simplest method to calculate days between dates
• How to manually calculate days (with formula)
• A faster method using our free Date Difference Calculator
• Examples, tips, and common questions

Let’s begin.

1. Use a Date Difference Calculator (Fastest Method)

The easiest way to calculate days between two dates is by using an online tool.

Use this calculator:
👉Date Difference Calculator

Just enter the start date and end date, and the tool instantly shows:

• Total number of days
• Weeks
• Months & years
• Hours & minutes
• Leap year adjustments

No manual counting, no errors, no formulas.

2. How to Calculate Days Between Two Dates Manually

If you want to calculate manually or for academic purposes, follow this simple method.

Step 1 — Note the two dates

Example:
Start: 10 February 2024
End: 25 July 2024

Step 2 — Break the range into months

Count days in each month:

• February (19 days left)
• March (31 days)
• April (30 days)
• May (31 days)
• June (30 days)
• July (25 days)

Step 3 — Add all days

19 + 31 + 30 + 31 + 30 + 25
= 166 days

That’s the total difference: 166 days

This method works, but it’s slow and error-prone — especially with leap years.

3. School Method: How to Calculate Days Between Two Dates Using Borrowing

The school method (also called the borrowing method) is a traditional way to calculate the difference between two dates without using a calculator. It is commonly used in:

• School mathematics
• Competitive exams
• Bank, HR and government forms
• Manual duration calculations

Let’s learn this easy and reliable method.

You write the later date on top and subtract the earlier date from it, column by column (Day, then Month, then Year).

             Year  Month  Day
Later Date    Y2    M2     D2
Earlier Date  Y1    M1     D1
             ----------------
Difference    Y     M      D

The special rules for “borrowing” are:

1. if D2 < D1 (Need to borrow a day):

• Borrow 1 month from the month column (M2), and reduce the month by 1
• Convert the borrowed month in days and add to the day column.
• Add the total number of days in the month preceding M2 to D2. (e.g., if M2 is May, the preceding month is April, so you add 30 days).

2. If M2 < M1 (Need to borrow a month):

• Borrow 1 year from the year column (Y2). and reduce the year by 1.
• Add 12 months to M2.

⭐ Example 1: Problem no borrowing needed

Find the difference between:

📅 Start Date: 8 March 2024
📅 End Date: 15 October 2025

  2025    10  15
- 2024    03  08
----------------
     1     7   7

Calculation:

In this example, there is no borrowing needed because the month and day of the start date are smaller than their respective month and day of the end date so we can simply subtract.

1. Days: 15 – 8 = 7 days. (No borrowing needed)
2. Months: 10 – 3 = 7 months. (No borrowing needed)
3. Years: 2025 – 2024 = 1 year.

The duration is 1 year, 7 months, and 7 days.

⭐ Example 2: Problem with borrowing

Find the duration between November 25, 2024 and May 10, 2025.

 2025   5   10
-2024  11   25
---------------

Step 1: Subtract Days

• Since 10 < 25, we must borrow a month from the Month column.
• The month preceding May (Month 5) is April (Month 4), which has 30 days.
• New Day: 10 + 30 = 40
• Day Difference: 40 – 25 = 15 days.
• New Month: 5 – 1 = 4.

 
 2025   5   10

 2025   4    40  (after borrowing for days)
-2024  11   25
---------------
            15

Step 2: Subtract Months

• Since 4 < 11, we must borrow a year from the Year column.
• New Month: 4 + 12 = 16
• Month Difference: 16 – 11 = 5 months.
• New Year: 2025 – 1 = 2024.

 
 2025   5   10

 2024  16    40  (after borrowing for days and month)
-2024  11   25
---------------
  0    5    15

Step 3: Subtract Years

• Year Difference: 2024 – 2024 = 0 years.

Result: The duration is 0 years, 5 months, and 15 days.

⭐ Why Borrowing Works in Date Calculations

Borrowing is needed when:

Condition	What to Borrow
End day < Start day	Borrow 1 month → convert to days
End month < Start month	Borrow 1 year → convert to 12 months

Days per month vary:

Month	Days
January	31
February	28/29
March	31
April	30
May	31
June	30
July	31
August	31
September	30
October	31
November	30
December	31

The borrowing method adjusts days correctly based on the month length.

---

⭐ Another Example (For Practice)

Try this one using the school method:

📅 Start: 03 April 2018
📅 End: 19 September 2023

Follow these steps:

1. Write in DD-MM-YYYY format
2. Borrow days if needed
3. Borrow months if needed
4. Subtract year, month, day
5. Write the final duration

This is excellent practice for exams and accuracy checks.

4. How to Calculate Days Between Dates Using a Formula

You can also calculate days using the universal date-difference formula:

Days = (End Date – Start Date)  

Most programming languages, like JavaScript, Python, and Excel, follow this rule.

Example in simple terms:

If you subtract 01 January 2024 from 10 January 2024:

10 Jan 2024 – 01 Jan 2024 = 9 days

5. Calculate Days Between Dates Using Excel (Easy Method)

If you prefer Excel or Google Sheets:

Formula

=DATEDIF(A1, B1, "D")

Where:

• A1 = start date
• B1 = end date

This gives the total days difference.

Calculate Days Between Dates with Leap Years

Leap years add one extra day (29 February).
Manually accounting for leap years is difficult, but our calculator automatically includes:

✔ 29 Feb 2020
✔ 29 Feb 2024
✔ Future leap years

This ensures accurate results every time.

Examples of Days Between Dates

Example 1

Start: 01 Jan 2025
End: 31 Jan 2025
Days: 30

Example 2

Start: 10 Mar 2024
End: 10 Mar 2025
Days: 366 (Leap year included)

Example 3

Start: 15 Aug 2022
End: 26 Jan 2025
Days: 895

Common Uses of Days Between Dates

People calculate date differences for:

• Age verification
• School records
• Job experience
• Visa/passport documents
• EMI and loan duration
• Pregnancy weeks
• Work/project planning
• Countdown to events
• Legal and government forms

This is why a Date Difference Calculator is incredibly useful.

Frequently Asked Questions (FAQ)

Related Tools

• Age Calculator
• Countdown Calculator
• Birthday Calculator
• Days Until Calculator
• Days Until New Year
• Days Until Christmas
• Date Difference Calculator
• Microsoft Rewards Program

Support

If you need any help regarding any method written in this post or with the calculator tool, or if you have any feedback, suggestions, or ideas. Please leave a comment or contact us via the contact us page. Thank you.