Date Difference Calculator
Find the exact difference between two dates in days, weeks, months, and years.
Select two dates to see the difference
How to Use the Date Difference Calculator
- 1
Pick Start Date
Select or type your first date in the Start Date field.
- 2
Pick End Date
Select your second date. The order does not matter — the calculator always shows the absolute difference.
- 3
Read the Result
The difference is shown in years, months, and days, plus total days, weeks, months, and hours.
- 4
Use for Planning
Great for deadline tracking, age verification, project durations, or event countdowns.
About the Date Difference Calculator
Computing the exact duration between two calendar dates is useful for contracts, deadlines, age verification, planning events, tracking anniversaries, and medical intervals. Simple day subtraction is straightforward, but expressing the result in years, months, and days requires careful handling of varying month lengths and leap years.
This calculator uses the same calendar-aware algorithm as professional date libraries: it subtracts year, then month, then day components, borrowing from the higher unit when a component goes negative.
The tool also provides total days, total weeks (with remaining days), total months, and total hours — each useful for different planning contexts. Payroll uses total days; scheduling software often uses hours; scientific work sometimes requires total weeks.
All computation is performed in the browser. No dates are sent to any server. The results update instantly as you change either date.
You may also find our Age Calculator, Time Calculator, and Countdown to Date helpful.
How to Use
- 1. Pick a start date.
- 2. Pick an end date.
- 3. The gap is shown in days, weeks, months, and years at once.
Frequently Asked Questions
Does the order of dates matter? expand_more
No — the calculator always shows the absolute difference regardless of which date is earlier.
Are leap years accounted for? expand_more
Yes — JavaScript Date objects handle leap years automatically in all arithmetic.
Can I calculate the number of business days? expand_more
This tool shows calendar days. Business day calculation requires knowledge of holidays and is not included.
How is "total months" calculated? expand_more
Total months = (years × 12) + remaining months, ignoring the leftover days.
Is the data stored? expand_more
No — everything runs locally in your browser.
Was this tool helpful?
Guide
How to find the number of days between two dates
Pick a Start Date and an End Date and the tool shows the gap as years, months and days, plus Total Days, Total Weeks (with leftover days), Total Months and Total Hours. The dates open pre-filled with today and a day 30 days later, so you can change one or both.
It counts calendar days between the two dates and ignores times of day. The order does not matter: if the start is after the end, the tool swaps them and shows a 'Dates swapped' note. It is useful for notice periods, project timelines, loan or warranty spans, and countdowns.
Step by step
- Click the Start Date field and choose a date from the picker, or type it in.
- Choose the End Date the same way. You can enter them in either order.
- Read the headline result, shown like '7m 27d'. Years and months are hidden when they are zero.
- Use the four boxes for Total Days, Total Weeks (such as 34 wk 1d), Total Months and Total Hours.
- For an inclusive count that includes both the first and last day, add 1 to Total Days yourself.
When this is useful
- Counting calendar days of a notice period between a resignation date and the last working day.
- Finding how long a rental, lease or subscription has run.
- Planning a project by checking weeks between kickoff and delivery.
- Working out how many days remain until a wedding, exam or travel date.
- Checking the gap between two invoice or payment dates.
Worked example: From 14 Feb 2026 to 11 Oct 2026
Start Date 14 Feb 2026, End Date 11 Oct 2026. The tool shows 7m 27d, which is 14 February plus seven months (14 September) and then 27 more days. Total Days is 239. Total Weeks is 34 wk 1d (34 x 7 = 238, plus 1). Total Months is 7 and Total Hours is 5,736 (239 x 24). If both the first and last day count, the inclusive figure is 240 days.
Tips for better results
- Total Days is the most dependable figure; use it when exactness matters.
- The tool does not count the end date. 1 to 31 January shows 30 days, not 31.
- Total Hours is simply Total Days times 24, so it ignores clock changes and times.
- For work-day counts, take calendar days and subtract weekends and holidays yourself.
- When the start date is the 29th, 30th or 31st, remember that a shorter month ends on its last day, so 31 January to 1 March reads as 1 month and 1 day.
Common mistakes
- Assuming the count is inclusive. Contracts that count both ends need one extra day, so add 1.
- Reading Total Months as a rounded figure. It is whole months only and drops leftover days.
- Using Total Hours for shift or elapsed-time work. It cannot represent times of day.
- Expecting business days or holidays. Only calendar days are counted.
Your files and privacy
The calculation happens in your browser from the two dates you pick, and the dates are not stored. The page records an anonymous visit with a random session ID, but no dates.
Frequently asked questions
Is the end date included in the count?
No. The tool subtracts one date from the other, so consecutive dates give 1 day. If your rule counts both the first and last day, add 1 to Total Days.
Are leap years handled?
Total Days is the exact number of days between the two calendar dates, so 29 February is counted when it falls in the range. For example, 1 March 2023 to 1 March 2024 gives 366 days.
How is the years-months-days line worked out?
It counts whole months from the start date first, then the leftover days. If the start day does not exist in a shorter month, that month ends on its last day, so 31 January to 1 March is 1 month and 1 day. Dates are read as calendar dates, so the result is the same in every time zone.
Does the order of the dates matter?
No. If the start date is later, the tool swaps them, shows a note, and reports the absolute difference.
Can it count only working days?
No. It counts calendar days only. Public holidays and weekends vary by country and employer, so subtract them yourself.
Guide reviewed 2026-10-11 by the useToolify team.
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