Date Difference Calculator

Pick a start date and an end date to see exactly how much time is between them — in days, weeks, months and years.

Start date End date

Include the end day in the count

Pick both dates to see the difference.

About this date calculator

Counting the days between two dates by hand is fiddly and error-prone. This calculator does it instantly: enter a start and end date and get the gap in days, weeks, months and years. It’s perfect for working out deadlines, project durations, notice periods, holidays, or how long until an event you’re looking forward to.

How to use it

Choose your start date.
Choose your end date (past or future).
Optionally tick “Include end day” to count both dates.
Read the difference in several units at once.

Frequently asked questions

Does it count the end day?

By default we count the gap between the two dates. Tick “Include end day” to count both the start and end dates.

Can I use future dates?

Yes — use it to count down to an event, a deadline, a holiday or a due date.

How are months and years calculated?

Years and months use real calendar dates, so months of different lengths and leap years are handled correctly.

Is my data private?

Yes. Everything is calculated in your browser; no dates are uploaded.