Date Calculator
Calculate duration between dates (D-Day), add or subtract time, and calculate business days excluding weekends.
Changing the timezone may shift the date boundary based on the current time.
Business Day Calc
About Date Calculator
The Date Calculator is a free, browser-based tool that calculates the gap between two dates, adds or subtracts days, weeks, months, or years from a date, and counts business days excluding weekends. It runs entirely in your browser, so the dates you enter never leave your device.
It groups three calculators in one place: Business Day Calc counts working days between two dates or finds the date that is a set number of business days away, Date Difference shows the total days, weeks, and approximate months between two dates (useful for D-Day counting), and Date Arithmetic adds or subtracts a mix of days, weeks, months, and years from a base date.
Use it to plan deadlines, count down to an event, or work out a delivery or payment date. You can pick a timezone for the calculation, and it auto-detects your local one by default; changing the timezone may shift a date boundary because it is based on the current time.
Business day mode only excludes Saturdays and Sundays, not public or regional holidays, so adjust manually for those. Date difference and arithmetic ranges are capped (about 10 years for differences and 5000 business days for additions) to keep results responsive.
Frequently asked questions
- Does the business day calculation skip public holidays?
- No. It only excludes Saturdays and Sundays. Any national or regional holidays need to be subtracted manually.
- Why does the result change when I switch timezones?
- Calculations are based on the current local time in the selected timezone, so changing it can move a date across a day boundary and shift the count by one day.
- Are my dates sent to a server?
- No. All calculations run locally in your browser using a JavaScript date library, with no network requests, so the dates you enter stay on your device.