About this tool
This date calculator does two jobs. In the first tab you enter a start date and a number of days, and it shows the date that many days after or before it, together with the weekday. In the second tab you enter two dates and it shows the number of days between them, the number of weeks and days, and a count that includes both end days. The start date itself is not counted, so 1 day after 2026-01-01 is 2026-01-02, and 100 days after 2026-01-01 is 2026-04-11. A 'weekdays only' option skips Saturdays and Sundays, so 10 weekdays after a Monday lands on the Monday two weeks later. Public holidays are not removed, so check the rules of your contract, visa or school before relying on a business-day count. Dates use calendar days, so time zones and time of day are ignored, and leap years are handled automatically. Everything is calculated in your browser and nothing is sent to a server.
How to use
- Pick the 'Date +/- days' tab, choose a start date and type the number of days.
- Choose 'days after' or 'days before' and turn on 'weekdays only' if you want to skip weekends.
- Or open 'Days between dates' and pick two dates to see the gap.
- Share the page with someone who needs it.