Date difference calculator
Count the days, weeks, months and business days between two dates – or add and subtract days, weeks, months and years to find a future or past date.
- Runs in your browser – private
- Instant results
- Free forever, no sign-up
How to use the Date Difference Calculator
- 1
Choose Days between two dates, or Add / subtract days.
- 2
Pick your dates or enter how many days, weeks, months or years to add.
- 3
Read the result, including business days and weekends.
Count days between two dates
Use this day counter for deadlines, notice periods, project timelines, rent and interest calculations, pregnancy weeks or countdowns to events. Tick Include end date when both the first and last day should be counted, as in leave applications.
Business days and working days
The calculator also counts business days (Monday–Friday) and weekend days. In add/subtract mode, tick Business days only to skip Saturdays and Sundays – handy for delivery dates, payment terms and SLA deadlines. Public holidays vary by state and company, so subtract those separately.
Add or subtract days from a date
Find the date 90 days from today, 6 months before a deadline or 2 years after a start date. Months are added on the calendar (31 January + 1 month moves into early March in non-leap years, as JavaScript dates do), so check end-of-month results where it matters. To calculate age, use the age calculator.
Frequently asked questions
How many days are there between two dates?
Select the start and end dates and the calculator shows the exact number of days, plus weeks, approximate months and business days.
Does it include the end date?
By default it counts the difference (end date not included). Tick “Include end date” to add one day.
How do I add 30 days to a date?
Switch to Add / subtract days, choose the start date, select Add and enter 30 in Days.
Can I calculate working days only?
Yes. Business days (Monday to Friday) are shown in difference mode, and you can skip weekends in add mode.
Is it free?
Yes – free with no sign-up.