Days Calculator

Find the exact number of days between two dates, broken down into weeks, calendar months, weekdays, and weekend days.

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Frequently Asked Questions

What is the difference between the "days" total and the "calendar span"?
The day total is a precise count of 24-hour periods between the two dates. The calendar span expresses the same gap using years, months, and days the way a calendar reads it, which accounts for different month lengths. For example, 73 days from January 1 to March 15, 2026 is also described as 2 months and 14 days because January has 31 days and February 2026 has 28.
When should I check "Count end date as a full day"?
Check it when both the start and end date should count toward the total, such as a hotel stay measured in nights plus checkout day, a work assignment where the last day is a full working day, or a rental period billed inclusively. Leave it unchecked when you want the plain gap between two dates, such as "how many days until my flight."
Why does the weekday and weekend count not match a business-day calculator?
This tool splits days strictly by day of week: Saturday and Sunday count as weekend, everything else counts as a weekday. It does not know about public holidays, so if your date range includes a holiday that falls on a weekday, a true business-day count would be one lower than the weekday figure shown here.
Does it handle leap years correctly?
Yes. The day count is based on real calendar dates using JavaScript's native date arithmetic, which correctly accounts for February having 29 days in a leap year. A span crossing a leap-year February will show a total day count consistent with that extra day.

What it is and when to use it

This calculator finds the number of days between a start date and an end date. By default it counts the way most people count elapsed time — the gap between the two dates, not the two dates themselves. Check "Count end date as a full day" if you want both the start and end date included in the total, which is common when counting things like rental days, hotel nights, or work assignments where the last day still counts.

Use it for planning deadlines, calculating a rental or lease period, checking how many days remain until an event, or figuring out exactly how long a project, trip, or job spanned. Beyond the raw day count, it breaks the span into weeks, a calendar years/months/days figure, and a weekday-versus-weekend split, which is useful for anything billed by business day or where weekends do not count toward a deadline.

How the calculation works

The calculator takes the two dates, always treats the earlier one as the start regardless of which field you typed it into, and counts full 24-hour days between them using each date's midnight timestamp. If "Count end date as a full day" is unchecked, it reports the gap only (exclusive counting); checking it adds one more day so both endpoints are included (inclusive counting) — this is the difference between "how many nights" and "how many days including check-in and check-out."

Worked example

From January 1, 2026 (a Thursday) to March 15, 2026 (a Sunday), with the end-date checkbox left unchecked: the gap is 73 days, equal to 10 weeks and 3 days, or a calendar span of 0 years, 2 months, and 14 days. Of those 73 days, 52 fall on a weekday and 21 fall on a weekend. Checking "Count end date as a full day" would raise the total to 74 days, since March 15 itself would now be included.

Common mistakes and how to interpret the result

  • Forgetting to check the end-date box for inclusive counts. Counting hotel nights, rental days, or "how many days was I there" usually needs the box checked; counting "how many days until" an event usually does not.
  • Mixing up the weekday/weekend split with business days. This calculator only separates Saturday/Sunday from Monday-Friday — it does not exclude public holidays, so a "weekdays" count is not the same as a business-days count if holidays fall in the range.
  • Misreading the calendar span. "2 months, 14 days" is a calendar-based breakdown (based on month lengths), while the day total (73) is the precise elapsed count — the two are consistent but answer slightly different questions and are not simply convertible into each other.
  • Entering the dates in the wrong order and expecting an error. The calculator automatically treats the earlier date as the start and flags the reversal with a note, so an accidental swap still produces the correct day count.