Days Between Dates
Calculate the duration between any two dates
Days Between Dates Calculator
This days between dates calculator takes any two dates and gives you the exact difference in days, weeks, months, and years.
It also shows you the working days (Monday through Friday) so you don't have to do a separate calculation for that.
Enter your dates, hit Calculate, and you get the full breakdown instantly.
A few things that make it faster to use: the End Date defaults to today, so if you're calculating "how long since X," you only need to fill in the start date. There's also a "Set to today" link under each field and a Swap Dates button if you entered them in the wrong order.
How the Date Calculation Works
The core calculation is simple: subtract the start date from the end date.
But the breakdown into weeks, months, and years requires more careful math because months and years aren't uniform lengths.
Days: The calculator finds the exact number of calendar days between the two dates. If you check "Include end date," it adds one more day to the total (this is called inclusive counting).
Weeks and days: Total days divided by 7 gives you the number of complete weeks, with any leftover days shown separately.
Years, months, and days breakdown: This follows calendar logic. Starting from the start date, it counts forward by full years, then full months, then remaining days. February is handled correctly regardless of whether it's a leap year.
Working days: The calculator counts only Monday through Friday, skipping weekends. This is the same logic Excel's NETWORKDAYS function uses. Holidays are not excluded since those vary by country and industry.
How to Interpret the Results
The calculator shows five different views of the same duration. Which one matters depends on your situation.
Total days is the most precise and unambiguous. Use this for deadline tracking, legal documents, or any situation where exact precision matters. There's no rounding or approximation involved.
Weeks is useful for project planning, sprint cycles, or anything that runs on a weekly schedule. The remainder days tell you how far into the next partial week you go.
Months is the natural unit for things like rent periods, subscription billing, or employment tenure. Keep in mind that "1 month" here means one calendar month, not exactly 30 days. January 15 to February 15 is 1 month (31 days), while February 15 to March 15 is also 1 month (28 or 29 days).
Years, months, days gives you the full human-readable breakdown. This is what most people want when communicating a duration to someone else. "2 years, 3 months, and 15 days" is clearer than "835 days."
Working days is what you need for anything tied to a business schedule — project timelines, payment terms, notice periods, or scheduling. Since it strips out Saturdays and Sundays, the number will always be lower than the total day count.
Inclusive vs. exclusive counting
This is a common source of confusion. By default, the calculator counts the days between the dates, not including the end date. This is standard date math (the same way Excel's DAYS function works).
But sometimes you need to count both the start and end date as full days. For example, if you're counting event days (a conference from June 1 to June 3 is 3 days, not 2). That's when you check "Include end date." The working days count adjusts automatically when this option is toggled.
Some Questions You May Have
Does this calculator account for leap years?
Yes. The calculator uses actual calendar dates for all calculations. If your date range includes February 29 in a leap year, it's counted correctly. You don't need to adjust anything manually.
What happens if I enter the end date before the start date?
The calculator automatically swaps the dates and calculates normally. You'll see a note in the results indicating the dates were swapped, but the result will be correct.
Does this calculator count working days?
Yes. The results include a working days count (Mon–Fri only, weekends excluded). Holidays are not excluded since those vary by location and industry.
Why does "1 month" sometimes equal 28 days and sometimes 31?
Because the calculator uses calendar months, not a fixed number of days. From January 15 to February 15 is 1 month (31 days). From February 15 to March 15 is also 1 month (28 or 29 days). This matches how people naturally think about months and is consistent with how contracts and billing periods work.
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