DAYS BETWEEN DATES

Ask how many days are between March 1 and March 3 and you'll get two different right answers. The difference is 2 days — that's what this calculator shows, and it's what deadlines, interest and rental periods use. But if you're counting the days themselves ("how many days will I be there?"), the answer is 3, because both ends count. Whenever a contract says "within 30 days," it means the difference; whenever a hotel counts nights, it means the difference too — the inclusive count is for days you'll actually be present.

This tool excludes Saturdays and Sundays to give a working-day count, which is what most project plans mean. But it does not know about public holidays — and the U.S. has around eleven federal ones, plus state-level days. If a legal or shipping deadline is defined in "business days," check whether a holiday falls inside your window; each one pushes the real date one day further out.

"Three months from now" is ambiguous by up to three days, because months run from 28 to 31 days. That's why loans, insurance policies and legal notices are almost always written in days — and why this calculator gives you the day count as the primary answer, with an approximate month figure only as a sanity check.

A number of days is only useful if it changes what you do today. Saving for something dated? Divide the amount by the days remaining to get your daily pace — and see what it grows to in our free high-yield savings calculator. Refinancing a mortgage is the same question in disguise: the break-even point is simply how many months of lower payments it takes to cover the closing costs, and our mortgage refinance calculator works that date out for you. Need the date itself rather than the gap? Use the add or subtract days tool.

The working-day figure above removes weekends but not public holidays, so here is the list to net out by hand: New Year's Day (1 Jan), Martin Luther King Jr. Day (3rd Monday of January), Washington's Birthday (3rd Monday of February), Memorial Day (last Monday of May), Juneteenth (19 June), Independence Day (4 July), Labor Day (1st Monday of September), the second Monday of October, Veterans Day (11 November), Thanksgiving (4th Thursday of November) and Christmas Day (25 December). Remember that a fixed-date holiday landing on a weekend shifts the observed day off to the adjacent Friday or Monday. If you would rather not do this manually, our business day calculator already skips both weekends and federal holidays.

Raw day counts stop being intuitive somewhere past about sixty. "Ninety-eight days" means little; "fourteen weeks exactly" means a great deal, especially in any context that runs on a weekly rhythm. Divide by seven and keep the remainder: 100 days is 14 weeks and 2 days. This is the native unit of pregnancy tracking, sprint planning, training programmes and course schedules — and it makes a span comparable to a calendar rather than just long. Where the weekly rhythm is formalised into numbered weeks, our week number tool tells you which ISO week any date falls in.

For long spans, the leap days are why a hand calculation drifts. A decade contains two or three of them depending on where it starts: 1 January 2020 to 1 January 2030 encloses three (2020, 2024 and 2028), while shifting the window one year later captures only two. Multiplying years by 365 therefore understates a long span by several days — and the century rule adds a further trap, since 2100 will not be a leap year despite being divisible by four. The calculator above counts real calendar days, so the leap days are already in the number.

Plenty of everyday questions are really day-count questions wearing different clothes: how long you have lived somewhere, how long since a first date, how long a project has been running, how long since a car's last service. The day figure is the honest one, since "about two years" hides anywhere up to a few hundred days of imprecision. For a birth date specifically, our age calculator gives the breakdown in years, months and days as well as the raw total — which is the form that passports, school registrars and insurers want.

Legal and administrative deadlines have their own counting conventions and they are not intuitive. Most U.S. rules exclude the triggering day, so "within 14 days of receipt" makes the day after receipt day one. Many court rules also extend a deadline that would fall on a weekend or holiday to the next business day. And periods written in years — statutes of limitation, warranty terms, lease renewals — are measured calendar-to-calendar rather than in days, so a leap year inside the span changes nothing. When a date genuinely matters legally, count it the way the governing document says to and treat the figure above as your cross-check, not your authority.