Date Difference Calculator

Enter Dates

Date Difference

Enter two dates to calculate the difference

How It Works

1

Enter Start Date

Select the first date using the date picker. This can be either the earlier or later date - our calculator will automatically determine the order.

2

Enter End Date

Select the second date. You can also choose whether to include the end date in the calculation.

3

View Detailed Results

After clicking Calculate, you'll see the difference between the two dates broken down into years, months, weeks, and days. You'll also see the total number of days between the dates.

Common Uses

Project Planning

Calculate project durations, deadlines, and milestone dates for effective project management.

Age Calculation

Determine exact age or time since a specific event like birthdays, anniversaries, or historical dates.

Contract Periods

Calculate contract durations, rental periods, subscription lengths, or loan terms.

Travel Planning

Calculate trip durations, visa validity periods, or days between departure and return dates.

Pregnancy Calculation

Track pregnancy weeks, calculate due dates, or determine conception dates.

Event Countdown

Find out exactly how many days until an important event, holiday, or deadline.

Frequently Asked Questions

How accurate is this date calculator?

This date calculator is highly accurate. It takes into account leap years, different month lengths, and provides results in multiple time units (years, months, weeks, days). The calculations follow standard calendar rules and conventions.

What's the difference between including and excluding the end date?

When you include the end date, the calculator counts both the start and end dates in the calculation. For example, if you calculate from January 1 to January 3 and include the end date, the result will be 3 days. If you exclude the end date, the result will be 2 days. Including the end date is useful for calculating periods where both the first and last days count (like vacation days).

Can I calculate the difference between dates in the past and future?

Yes! You can calculate the difference between any two dates, whether they're both in the past, both in the future, or one in the past and one in the future. Our calculator automatically determines which date comes first and calculates the difference accordingly.

Why might the years, months, and days not add up to the total days?

The total days is a straightforward count of all days between the two dates. However, when breaking this down into years, months, and days, we account for varying month lengths and leap years. For example, a month can be 28, 29, 30, or 31 days, so "1 month" doesn't always equal 30 days. This is why the sum of the broken-down units might not exactly match the total days count.