Date Difference Calculator
Calculate the exact number of days, weeks, months, and years between two dates. Also shows weekdays, weekend days, and total hours.
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Dimensions: 100% width, 650px height, fully responsive.
Attribution: Includes "Powered by CalculatorSwitch.com" footer with backlink (required for free use).
Styling: Clean minimal design with rounded border, optimized for embedding.
Purpose
The date difference calculator helps you find the exact time between any two dates. Whether you're counting down to an event, tracking project timelines, calculating age differences, or determining rental periods, this tool gives you precise results in multiple formats. It shows the difference in years, months, days, weeks, hours, and even separates weekdays from weekend days for business planning.
How to use
Using the date difference calculator is simple:
- Enter Start Date: Select the earlier date or the date you want to start counting from
- Enter End Date: Select the later date or the date you want to count to
- View Results: The calculator instantly shows the difference in multiple formats
The results include:
- Years, months, and days between the dates
- Total days, weeks, hours, and minutes
- Number of weekdays (business days)
- Number of weekend days
Note: The order of dates doesn't matter - the calculator will automatically determine which date is earlier.
Examples
Example 1: Planning a Project Timeline
Start Date: January 15, 2026
End Date: April 30, 2026
Result:
- 3 months, 15 days
- 105 total days
- 75 weekdays (business days)
- 30 weekend days
Example 2: Calculating Rental Period
Move-in: March 1, 2026
Move-out: February 28, 2027
Result:
- 11 months, 27 days
- 365 days
- 52 weeks and 1 day
Example 3: Event Countdown
Today: January 11, 2026
Wedding Date: June 15, 2026
Result:
- 5 months, 4 days
- 155 days until the event
FAQ
Does this calculator include or exclude the end date?
The calculator counts the days between the two dates, not including the end date itself. For example, from January 1 to January 3 is 2 days (January 1 and January 2). If you need to include the end date, add 1 to the result.
How are leap years handled?
Leap years are handled automatically. When February has 29 days in a leap year, the calculator correctly accounts for the extra day. This ensures accurate results for date ranges that span leap years.
What counts as a weekday?
Weekdays are Monday through Friday (5 days per week). Weekend days are Saturday and Sunday. The calculator does not account for holidays - all Mondays through Fridays are counted as weekdays regardless of whether they are public holidays.
Can I calculate dates in the past?
Yes! The calculator works with any dates - past, present, or future. You can calculate the time since a historical event or the time until a future date. The order of dates doesn't matter; the calculator will determine which is earlier automatically.
Why might my result differ by one day from other calculators?
Different calculators may use different counting conventions. Some include both start and end dates, some include only one, and some exclude both. Our calculator counts the days between the dates, not including the end date. This is the most common convention for duration calculations.
Methodology
The calculator uses precise date arithmetic to compute differences:
Basic Calculation:
- Convert both dates to milliseconds since epoch
- Calculate the difference in milliseconds
- Convert to days: difference / (1000 * 60 * 60 * 24)
Years/Months/Days Calculation:
- Calculate year difference between dates
- Adjust months: If current month < start month, subtract a year and add 12 months
- Adjust days: If current day < start day, subtract a month and add days from previous month
Weekday Calculation:
- Iterate through each day between the dates
- Count days where day of week is 1-5 (Monday-Friday)
- Weekend days = Total days - Weekdays
Validation & Accuracy
Tested: Verified against multiple date calculation tools and spreadsheet functions.
Accuracy: Correctly handles leap years, varying month lengths, and timezone-neutral calculations.
Limitations:
- Timezone differences are not considered
- Assumes Gregorian calendar throughout
- Does not account for holidays in weekday calculations