Date Difference Calculator — Days Between Two Dates

How many days between two dates? How many weeks until a deadline? How many months since an event? These are simple questions but working them out manually — counting calendar squares, converting weeks to days, accounting for leap years — is tedious and error-prone.
This free tool gives you the exact gap between any two dates in days, weeks, months and years simultaneously. Enter a start date and end date and every figure appears instantly.

How to Calculate the Difference Between Two Dates

The date difference between two dates is the total number of days from the start date to the end date. For same-month calculations you subtract the start day from the end day. For dates spanning multiple months and years the calculation must account for the exact number of days in each month and whether any February falls in a leap year.
Example: The difference between 1 January 2024 and 1 July 2024:

January: 31 days
February: 29 days (2024 is a leap year)
March: 31 days
April: 30 days
May: 31 days
June: 30 days
Total: 182 days = 26 weeks = 6 months

The calculator handles all of this automatically regardless of how far apart the dates are.

What Is a Leap Year and Why Does It Matter?

A leap year occurs every four years and adds one extra day — 29 February — to the calendar. The rule is: a year is a leap year if it is divisible by 4, except for century years which must be divisible by 400.
This matters because any date range spanning a February in a leap year contains one more day than the same range in a non-leap year. Every leap year is accounted for automatically — you never need to check manually.
Upcoming leap years: 2024, 2028, 2032, 2036, 2040.

Common Date Difference Calculations

different time durations- date difference calculator

Days until a deadline — enter today as the start date and your deadline as the end date. The result shows exactly how many days you have left.

Days since an event — enter the event date as the start date and today as the end date. The result shows how many days have passed since that date.

Age in days — enter your date of birth as the start date and today as the end date. The result shows your exact age in days, weeks, months and years. For a dedicated age calculator with more detail use the Age Calculator.

Contract or subscription duration — enter the start and end dates of a contract to confirm its exact length in days and months — useful for verifying notice periods, subscription terms and lease durations.

Date Difference vs Time Duration — What Is the Difference?

A date difference calculator measures the gap between two calendar dates — days, weeks, months and years.
A time duration calculator measures the gap between two times on the same day or across midnight — hours, minutes and seconds.

Use the date difference calculator for calendar-based questions like “how many days between 1 March and 30 June.” Use the time duration calculator for clock-based questions like “how many hours between 9 AM and 5:30 PM.”

Other Free Tools

Days Calculator — Add or subtract days from any date
Age Calculator — Exact age in years, months and days from date of birth
Time Duration Calculator — Hours and minutes between two times
Days Until Christmas — Live countdown to 25 Decembe

Frequently Asked Questions

Enter your start date and end date above. The number of days appears instantly alongside weeks, months and years. The calculator accounts for leap years and varying month lengths automatically.

From 1 January to 31 December is 364 days in a standard year — not 365, because the calculator counts from the day after the start date to the end date. To get 365 days include 1 January itself by adding 1 to the result, or enter 31 December of the previous year as your start date.

The date difference calculator shows complete months between any two dates alongside the remaining days. The difference between 1 January and 15 March is 2 complete months and 14 days — not simply 2 months, because the 15 extra days matter for contracts and billing.

No — the calculator counts from the day after the start date to the end date inclusive. This is the standard convention. If you want to include the start date add 1 to the result.

Six months is approximately 181 to 184 days depending on which six months. January to June is 181 days in a standard year and 182 in a leap year. June to December is 184 days. Use the calculator with your specific dates for the exact figure.

A date difference calculator measures the gap between any two dates — past, present or future. A countdown measures the time remaining until a specific future date and updates in real time. For live holiday countdowns see the Days Until Christmas and Days Until New Year pages.

Yes — every leap year is accounted for automatically. Any date range spanning a February in a leap year correctly includes 29 February in the total count without any adjustment needed from you.

Enter the dates and the date difference calculator returns the exact count. For example 1 January 2023 to 1 January 2025 is 730 days — two standard years. If the range includes a leap year February the total increases by one.

About This Date Difference Calculator

This date difference calculator is part of CalcDaysTime — a free suite of date, time and maths tools. All calculations run entirely in your browser. No data is sent to our servers, stored or shared with anyone.

Disclaimer: Results are calculated based on the dates you enter using the Gregorian calendar. Always verify date calculations against official records for legal or contractual purposes.