How do I calculate the number of days between two dates?

Subtract the earlier date from the later date. The calculator handles leap years and time zones, and can also exclude weekends if you only want business days.

What are business days?

Monday through Friday, excluding public holidays. The calculator's business-days mode skips weekends; toggle holidays separately if your jurisdiction requires.

Date Difference Calculator (Days Between Dates)

How to Calculate Days Between Dates

Computing the exact time between two dates requires accounting for varying month lengths (28-31 days), leap years, and the difference between calendar time and business time. This calculator handles all of these complexities for you.

Common Uses

Project planning: Calculate business days for deadlines and milestones
Age calculation: Find your exact age in days for milestone birthdays
Travel planning: Count days for visa duration, hotel stays, or trip length
Legal deadlines: Calculate statute of limitations or filing deadlines
Pregnancy tracking: Count weeks and days from conception or last period

Frequently Asked Questions

How do you calculate the number of days between two dates?

Subtract the earlier date from the later date and convert the result from milliseconds to days (divide by 86,400,000). This calculator accounts for leap years and varying month lengths automatically.

Does this count the start and end dates?

This calculator counts the difference between the two dates. For example, January 1 to January 2 is 1 day. If you need to include both dates (e.g., for a rental period), add 1 to the result.

How many weekdays are between two dates?

This calculator counts both weekdays (Mon-Fri business days) and weekend days (Sat-Sun) separately. This is useful for calculating business days, work schedules, and project timelines.

How do I calculate my age in days?

Enter your birthdate as the start date and today's date as the end date. The result shows your exact age in days, weeks, months, and years — perfect for milestone celebrations!

How many days are in a year?

A regular year has 365 days. A leap year (every 4 years, except centuries not divisible by 400) has 366 days. On average, a year is 365.2425 days long, which is why we have leap years to keep the calendar aligned with Earth's orbit.

Date Difference Calculator