Date Diff — what it does
Counts the exact duration between two dates in days, weeks, months and years — plus business days when you exclude weekends. Built for project timelines, contract periods, notice periods, visa durations and pregnancy/assignment tracking, where 'about three months' is not good enough.
How to use Date Diff
- Set the start and end dates.
- Read the total duration in days plus its years/months/days breakdown.
- Toggle 'exclude weekends' to get business days for deadline math.
- Check the weekday panel to see which days of the week the two dates fall on.
- Past or future — either direction works; the tool labels which date is earlier.
Worked example: a 90-day notice period
Resignation on 15 January with a 90-day notice: the tool lands on 15 April as day 90, and shows the business-day count if the contract counts working days instead. The weekend toggle is the feature here — '90 days' and '90 working days' differ by about 26 days, a difference that has cost people their join dates.
At a glance
| Output | Days, weeks, months+years breakdown; optional business days |
|---|---|
| Direction | Past or future intervals, order-independent |
| Extras | Weekday labels for both endpoints |
| Privacy | Runs in the browser — no dates stored or sent |
| Limits | Calendar days and weekends only; it does not know public holidays |
Frequently asked questions
- What is Date Diff?
- Find the exact difference between two dates in every unit.
- Is Date Diff free to use?
- Yes — Date Diff is free to use, with no sign-up, no install and no account.
- Does Date Diff upload or store my data?
- No — Date Diff runs entirely in your browser, so your text, files and results never leave your device.
- Do I need to install anything to use Date Diff?
- No — it works in any modern browser (Chrome, Edge, Firefox, Safari) with no downloads, accounts or plugins.
- Does 'excluding weekends' also skip public holidays?
- No — holiday calendars are country and state specific, so the tool only removes Saturdays and Sundays. If your policy counts holidays, subtract them manually from the business-day figure.
- Is the end date included in the count?
- The count is the difference between the dates (end minus start). If your contract says 'inclusive of both days', add one day to the result.
- Can I measure an interval that spans years?
- Yes — the years/months/days breakdown stays exact across leap years, and the raw day count is shown alongside for contract language.