Days Between Two Dates (Detailed) Calculator
A full breakdown of the gap between two dates — total days, years-months-days, weeks, hours, how many of each weekday, leap days, working days without US, Mexican or Spanish holidays, and a month-by-month table.
How it works
days = end − start (+1 if both ends count, −1 if neither does) · weeks = days ÷ 7 · years-months-days by calendar walking · weekdays = Mon–Fri dates in the span · weekend = days − weekdays · working days = days − days off − holidays · hours = days × 24
The core figure is the serial difference between the two dates, so leap days and month lengths are already inside it. You choose how the ends are treated: the plain gap (the start date is left out, the end date counted), both dates counted — handy for bookings, rentals and billing periods — or only the dates strictly in between. The span is then broken down every way people ask about it: years, months and days by walking the real calendar, total months, weeks, decimal years, hours, minutes and seconds, the number of each weekday (how many Mondays, Tuesdays and so on), the Monday-to-Friday and weekend split, and the Feb 29 leap days it contains. Pick a public-holiday set (US federal, Mexico’s official rest days with or without bank holidays, or Spain’s national holidays) or a different weekend to get working days too, with a month-by-month table and the list of holidays found.
Worked example
From 1 Jan 2026 to 15 Sep 2026 is 257 days between the dates — 8 months and 14 days, 36.7 weeks or 6,168 hours. Leaving out January 1 and counting September 15, 183 of those days are weekdays (37 Mondays, 37 Tuesdays, 36 Wednesdays, 36 Thursdays and 37 Fridays) and 74 fall on a weekend; there is no February 29 in 2026. Choosing US federal holidays takes out the 6 that land on counted weekdays — MLK Day, Presidents’ Day, Memorial Day, Juneteenth, the observed Independence Day (Friday, July 3) and Labor Day; New Year’s Day is not among them because January 1 itself is not counted — leaving 177 working days. Counting both end dates makes it 258 days.
Sources: OPM — Federal holidays · Ley Federal del Trabajo (México), art. 74
Frequently asked questions
What does "count both end dates" change?
Left at “No”, you get the gap between the dates: the start date is not counted, the end date is. “Yes” counts both the first and last day, adding one — useful for bookings and billing. “Neither” counts only the dates strictly in between, one less than the gap.
Why is the months figure not days ÷ 30?
Months are 28 to 31 days long, so dividing by 30 drifts. The breakdown walks the actual calendar so it matches how people state durations.
Can public holidays be removed?
Yes. Choose US federal holidays, Mexico’s official rest days (optionally with the bank holidays of Holy Week, November 2 and December 12) or Spain’s national holidays, and the working-day count, monthly table and holiday list appear. Regional and local holidays are not included.
How do I find how many Mondays (or any weekday) are between two dates?
Look at the “Days of the week in the span” table and chart: it counts every Monday through Sunday in the dates being counted, following the end-date setting you chose.
Does it count leap days?
Yes. The day count already includes any February 29, and the leap-day figure tells you how many there are in the span.
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This calculator is for educational purposes. Double-check important results before acting on them.