📅 Date Difference Guide

Days Between Two Dates Calculator

Updated June 2026 · 5 min read · Free calculator included

Quick answer: Subtract the earlier date from the later date. Use our free Date Difference Calculator to get the result instantly in days, weeks, months, and years.

Counting days between two dates comes up constantly — deadlines, contracts, loan durations, travel planning, age calculations. This guide shows you how to do it manually, in Excel, and with a free calculator.

How to Calculate Days Between Dates Manually

Same year

Days = Day-of-year (End) − Day-of-year (Start)

Example: March 15 to September 20 → Day 263 − Day 74 = 189 days

Across different years

Count days remaining in start year + full years in between (365 or 366 for leap) + days elapsed in final year.

Common Examples

Period	Approximate Days
1 week	7 days
1 month (average)	30.44 days
1 quarter	91 days
6 months	182–184 days
1 year (regular)	365 days
1 year (leap)	366 days

How to Calculate in Excel

Basic subtraction:

= B2 - A2

Format the result cell as Number (not Date) to see the day count.

DAYS function (Excel 2013+):

= DAYS(B2, A2)

Working days only (excludes weekends):

= NETWORKDAYS(A2, B2)

Years, months, days with DATEDIF:

= DATEDIF(A2, B2, "D") → days = DATEDIF(A2, B2, "M") → complete months = DATEDIF(A2, B2, "Y") → complete years

Calendar Days vs Working Days

Use case	Which to use
Loan interest calculation	Calendar days
Project deadline	Working days
Age calculation	Calendar days
Delivery estimate	Working days
Contract duration	Calendar days (usually)

📅 Count Days Between Any Two Dates

Get the result in days, weeks, months, and years. Works for past and future dates.

Open Date Difference Calculator →

Frequently Asked Questions

Does the calculator include the start and end date?

For most purposes — duration between events — only one end is counted. Our calculator shows both options so you can choose.

How many days is 3 months?

Approximately 90–92 days depending on which months. Use the calculator for exact results between specific dates.

What is the difference between DATEDIF and DAYS in Excel?

DAYS simply returns the number of days. DATEDIF is more flexible — it can return complete months or years, making it better for age calculations.

Do leap years affect the count?

Yes, if your date range includes February 29. Our calculator handles leap years automatically. Recent leap years: 2020, 2024, 2028.