Days Between Dates Calculator

Count the exact number of days, weeks, months and years between any two dates. Includes business days, quick presets and a progress timeline.

Quick presets

Start date

End date

Include end date Show business days (Mon–Fri)

Select start and end dates above to calculate

How to calculate days between dates

Select your start and end dates above — the tool calculates the difference instantly. By default it counts the start date but not the end date (the same way most date calculators work). Tick Include end date to add one extra day to the count.

The calculation subtracts the start date from the end date in milliseconds, then converts to days. Weeks are days ÷ 7 (rounded down). Months are the number of complete calendar months. Years are complete calendar years.

Common uses for this calculator

Project deadlines — count exactly how many days remain before a project, exam, or event.
Contract periods — verify notice periods, lease durations, or subscription lengths in days.
Age in days — find out how many days old you are by entering your birth date as the start date.
Pregnancy — count how many days since a last menstrual period or conception date.
Business billing — calculate the number of days in a billing period or invoice payment window.
Fitness challenges — track how many days into a 30-day or 90-day challenge you are.
Legal deadlines — count business days for response windows, filing deadlines, or notice periods.
Anniversary — find out how many days since a special date like a wedding or milestone.

Business days vs. calendar days

Calendar days count every day including weekends and public holidays. Business days count only Monday to Friday. Toggle Show business days above to see both.

Note: this calculator counts Mon–Fri as business days but does not account for public holidays, which vary by country and region. For legal or contractual purposes, always verify the specific holiday schedule that applies to your situation.

Frequently asked questions

How many days are between two dates?▾

Enter your start and end dates in the calculator above. The result shows the exact number of days, weeks, months and years between them. You can also toggle to include or exclude the end date.

How do I count days between dates in Excel?▾

In Excel, subtract the start date from the end date: =B1-A1 where A1 is the start date and B1 is the end date. Format the result cell as a number to see the day count. For business days only, use =NETWORKDAYS(A1,B1).

What is today 5 years ago?▾

Use the "Last 5 years" preset above — it sets the start date to exactly 5 years before today and the end date to today, showing you the number of days in that span. You can also enter any past date manually to compare with today.

How do I subtract dates to find the difference?▾

The simplest way is to use this calculator — just enter both dates. Manually, convert both dates to a day number (Julian Day Number), then subtract. This automatically handles months of different lengths and leap years.

How many calendar days are in a year?▾

A regular year has 365 days. A leap year (divisible by 4, except century years not divisible by 400) has 366 days. On average, a year is 365.2425 days long, which is why we add a leap day every 4 years to keep the calendar in sync with the solar year.

Does the calculator include weekends?▾

By default it counts all calendar days including weekends. Toggle Show business days to also see the count excluding Saturdays and Sundays. Note that public holidays are not excluded — they vary by country and are not included in this calculation.

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