Wyvek

Date Difference Calculator

Count days, weeks & months between dates.

Choose a start date and an end date to see the difference.

Free online date difference calculator

This date difference calculator tells you exactly how much time lies between two dates — the answer to "how many days between these dates?" in a single click. Pick a start date and an end date and it instantly works out the duration in years, months, and days, then breaks it down into total days, total weeks with the leftover days, an approximate total of months, and total hours. It's ideal for counting down to deadlines, working out project lengths, notice periods, pregnancy weeks, or anniversaries. Everything runs in your browser, so your dates stay private.

How to find the difference between two dates

  1. Pick your Start date in the first field.
  2. Choose the End date — it defaults to today.
  3. Tick Include end date if the final day should count too.
  4. Read the exact years, months, and days as the result updates live.
  5. Check the totals, then click Copy summary for forms or messages.

How the calculation works

The tool subtracts the day, month, and year parts and borrows across months the same way you would by hand, clamping the borrowed day to the shorter month so you never see a negative figure. If the end date falls before the start date, it uses the absolute difference and simply notes which date is earlier. Working out someone's age instead? Try the age calculator. Comparing epoch values? Use the Unix timestamp converter.

Private and instant

There is no sign-up and nothing is uploaded — the calculation happens locally on your device. Bookmark this page the next time you need a fast, accurate count of the days between two dates.

Frequently asked questions

How does the date difference calculator work?

Pick a start date and an end date and the tool works out the duration between them. It subtracts the day, month, and year parts and borrows correctly across months, so you get an exact result in years, months, and days — plus totals in days, weeks, months, and hours. Everything is calculated in your browser as you type.

How are the years, months, and days calculated?

We subtract the start day from the end day; if the result is negative we borrow the number of days in the month before the end date and reduce the month count. If months then go negative, we borrow 12 months and reduce the year count. The borrowed day is clamped to the shorter month's length, so a span like 31 January to 1 March never produces a negative day.

What does "Include end date" do?

By default the end date is not counted as a full day, so 1 January to 2 January is 1 day. Tick "Include end date" to count the final day too, which adds 1 day to every total. This is useful when you are counting nights versus days, project durations, or notice periods.

What if my end date is before my start date?

The calculator uses the absolute difference, so the order does not matter — it swaps the dates internally and shows the same duration either way, with a note telling you which date is earlier.

How is the total number of months worked out?

The total months figure is the years-and-months breakdown expressed in months (years times twelve plus the remaining months). Because calendar months vary in length, treat it as an approximate count rather than an exact 30-day figure.

Are my dates kept private?

Yes. This date difference calculator runs entirely in your browser using JavaScript. The dates you enter are never uploaded, stored, or shared, so it is safe to use for private or sensitive planning.

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