Date Calculator
Add days or find the span between dates.
Loading tool
Ask how many days until a deadline, or what date is 90 days from today. Month arithmetic follows civil calendar rules.
How to use this tool
- Set the dates or duration. Pick the clocks, dates, or timer length you need.
- Start or calculate. Run the timer or read the difference. Time zones use this browser.
- Copy the result. Copy timestamps or calendar values into your notes.
Month ends
Adding one month to 31 January lands on the last day of February in this calculator, not 2 or 3 March.
Frequently asked
Are end dates inclusive?
You can count inclusive or exclusive. Hotel-night style is exclusive of the last date.
Does it skip holidays?
No. Use business days for weekday-only spans.
Can I add hours?
Yes. Hours and minutes are optional on top of calendar units.
What calendar is used?
Gregorian, via the JavaScript Date and Temporal-style civil rules in the page.
Is this legal time computation?
No. Courts and contracts may define days differently.