Date Difference Calculator
Measure the span between two calendar dates in days, weeks, months, and years. Optionally include the end date in the count.
Runs locally in your browser
- Days
- 980
- Weeks
- 140.00
- Months
- 32.20
- Years
- 2.68
Pick a start and an end when you are planning a trip, a contract, or a sprint. This is a span between two dates, not age from a birthday.
Day counts use local midnight in this browser. The dates stay on the device.
How to use
- 1Enter the start date and the end date.
- 2Toggle whether the end date counts as a full day.
- 3Read days, weeks, months, and years.
How it works
The core unit is whole days between local midnights. Weeks divide by 7. Months and years use average month and Gregorian year lengths for a decimal view.
Include end adds one day, which matches hotel-night versus calendar-day debates when both dates should count.
Examples
Trip length
Leave on the 1st and return on the 8th is 7 days, or 8 if you include the return date as a full day.
Contract window
A 90-day notice from 1 April lands near late June in the day total, with a decimal year under 0.25.
FAQ
Can the end be before the start?
Yes. The day count can be negative, which flags a reversed range.
Is this the same as age?
No. Age uses a birthday and calendar borrow. This page measures a span between two picked dates.
Are months exact calendar months?
The month figure is days divided by 30.4375, an average, not a civil month walk.
Do dates leave the browser?
No. Difference math is local.
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