Is the start date or end date included in the count?

The standard convention counts from the day after the start date through the end date. So January 1 to January 3 is 2 days. If you need to include both endpoints, add 1 to the result.

How do leap years affect the count?

In leap years, the period from January 1 to December 31 is 365 days instead of 364. Any span crossing February 29 in a leap year includes the extra day automatically.

Why is this different from a date difference calculator?

This tool gives you a single number: total days. The date difference calculator decomposes the result into years, months, and remaining days, which is more intuitive for some purposes but less useful for calculations requiring a day count.

Can I use this for financial calculations?

Yes. Day counts are the foundation of interest calculations. The actual/actual day count convention used here is common in bond markets. Other conventions (30/360, actual/360) modify the count for specific financial instruments.

Does it account for time zones?

The calculator works with dates only (not times), so time zones do not affect the result. January 1 to January 10 is always 9 days regardless of where you are in the world.

Days Between Calculator

Count the exact number of days between two dates

Days Between Dates

Calculate the number of days between two dates

Days Between Dates

Enter two dates

Start Date (YYYY-MM-DD)

End Date (YYYY-MM-DD)

Formula

Days = |End Date - Start Date|

What Is the Days Between Calculator?

The days between calculator gives you the precise number of calendar days separating two dates. It's used for calculating days remaining until an event, days since something happened, billing periods, rental durations, age in days, loan terms, and subscription lengths. Simple yet surprisingly easy to get wrong — our tool handles month boundaries and leap years automatically.

You can choose to count all calendar days or count only business days (Monday through Friday). The result also shows the equivalent number of weeks and whether any leap year day (February 29) falls within the range.

How to Use the Days Between Calculator

Enter the start date using the date picker or by typing it in directly.
Enter the end date for the period you want to measure.
Choose whether to count all calendar days or business days only (Monday–Friday).
Click Calculate to see the total day count, the number of complete weeks, and any remaining days.

Formula and Reference

Calendar days between dates:
  Days = (End date − Start date) in milliseconds / 86,400,000

Inclusive count (includes both endpoints):
  Days = Calendar days + 1

Exclusive count (standard, excludes end date):
  Days = Calendar days

Business days (approximate):
  = Days − floor(Days / 7) × 2 − partial weekends

Days in a year: 365 (366 in leap years)
Days in each month: 28–31 (see calendar)

"Between" typically means exclusive — Jan 1 to Jan 8 is 7 days, not 8. Use inclusive counting for "how many days including today."

Worked Examples

Days from January 1 to December 31, 2025

From January 1 to December 31, 2025 (exclusive of the end date) there are 364 calendar days. 2025 is not a leap year, so the year has 365 days total — counting from Jan 1 through Dec 31 inclusively gives all 365.

When does a 30-day free trial starting April 1 expire?

A 30-day trial that starts on April 1 runs through April 30. Day 1 is April 1, day 30 is April 30, so the trial expires at the end of April 30. If the trial is measured exclusively (start date not counted), it ends May 1.

A 90-day loan starting March 1 — what is the due date?

90 days after March 1: March has 31 days, so 30 days brings you to March 31. April has 30 days, so another 30 days lands on April 30. The remaining 30 days end on May 30. The loan due date is May 29 (exclusive) or May 30 (inclusive).

Frequently Asked Questions

What is the difference between inclusive and exclusive day counting?▾

Exclusive counting (the standard) does not count the end date itself — Jan 1 to Jan 8 = 7 days. Inclusive counting counts both the start and end date — Jan 1 to Jan 8 = 8 days. Use inclusive when you need "how many days are there from Monday through Sunday" (the answer is 7, not 6).

How do I count only weekdays between two dates?▾

Select the 'Business Days' option in the calculator. The tool removes Saturdays and Sundays from the count. Public holidays are not automatically removed — subtract them manually if needed for your country or region.

Does the calculator include or exclude the start and end dates?▾

By default the calculator uses exclusive counting: the start date is day zero and the end date is not counted. This matches how most scheduling and billing systems work. You can switch to inclusive mode to count both endpoints.

How many days are in a year?▾

A standard calendar year has 365 days. A leap year has 366 days — February 29 is added every four years (with exceptions for century years not divisible by 400). Our calculator detects whether February 29 falls in your date range automatically.

How many days are between January 1 and July 4?▾

From January 1 to July 4 (exclusive) there are 184 days in a non-leap year: January (31) + February (28) + March (31) + April (30) + May (31) + June (30) + 3 days of July = 184. In a leap year (February has 29 days) the total is 185 days.