Days Between Dates Calculator_

How to calculate the days between two dates

Subtract the start date from the end date: the result is the number of days between them. From 1 March to 15 March is 14 days. Add 1 if you want to count both the first and the last day (15 days) — that is the Include end date switch in the calculator above.

The Days Between Dates Calculator does this for any two dates, from the 1600s to far into the future, and gets leap years, month lengths and daylight saving time right. It also counts business days without weekends and public holidays, adds or subtracts days from a date, works out an age, runs a countdown and converts date formats. It is free, there is no account and no ads, and everything is calculated in your browser.

Counting by hand, across months

Count the days left in the start month, add the full months in between, then add the day of the end month. 10 January → 5 March 2026: 21 (rest of January) + 28 (February) + 5 = 54 days. For long spans, it is quicker to count whole years first: a year from a date to the same date next year is 365 days, or 366 when a 29 February falls in between.

Should you include the end date?

This is where most disagreements about a day count come from, and the two answers always differ by exactly one. Without the end date you measure the gap between two dates: 3 to 5 March is two days, the way you count hotel nights, interest days or an age. With the end date you count every date in the range: 3 to 5 March is three days, the way you count days of a festival, days of annual leave or days worked. Decide which question you are asking, then set the switch. A different result from another calculator is almost always this setting.

Business days and working days

Switch on Business days and Saturdays and Sundays drop out of the count. Pick a country under Skip public holidays in and its national public holidays that land on a working day are left out too, and listed below the result. The holidays are calculated for any year, including the ones that move with Easter: Good Friday, Easter Monday, Ascension Day, Whit Monday and Corpus Christi. The built-in countries are Belgium, the Netherlands, Luxembourg, Germany, France, the UK (England & Wales), Ireland, the United States (federal), Spain, Italy, Austria, Portugal, Poland, Denmark, Sweden and Norway. Regional holidays — a German state, a Spanish region, a US state — and company closing days are not included, so subtract those yourself.

Not everyone works Monday to Friday. Click the day letters next to Work week to set your own: Sunday to Thursday as in much of the Middle East, a four-day week, or six days for retail and hospitality. The business-day count and the "add business days" calculation both follow your choice.

In a contract, "working day" usually means any day other than a Saturday, Sunday or public holiday, and many contracts define it in so many words. If yours does, that definition wins over any calculator. For "within 5 business days of receipt", the count normally starts the day after receipt: put the receipt date in Add or subtract, choose 5 business days, and read off the deadline.

Adding or subtracting days, weeks and months

Use Date arithmetic to go from a date to a date: 30 days after an invoice date, 90 days from today, 18 months after a start date, two weeks before a wedding. Days and weeks are exact. Months and years follow the calendar, and when the target month is shorter the date is clamped to its last day: 31 January plus one month is 28 February (29 in a leap year), not 3 March. That is the convention spreadsheets use too, with =EDATE(A1,1).

Weeks, months and years in a span

Days are exact; weeks are the days divided by seven. Months and years are counted on the calendar: from 15 January to 20 March is 2 months and 5 days, whatever the length of February. That is why the same number of days can be "1 month and 1 day" in one part of the year and "30 days" in another. For anything contractual, quote the day count, which cannot be read two ways.

Age calculator

Enter a date of birth and you get the age in completed years, months and days — the way people actually state an age — plus the days, weeks and hours lived and the days until the next birthday. Set a reference date to find out how old someone was or will be on a particular day, for a school year, an exam, an insurance policy or an eligibility rule. Someone born on 29 February has a birthday on 1 March in common years in this calculator; legal rules on this differ by country, so check the one that applies if a threshold depends on it.

Countdown to a date

Pick a date and, if you like, a time and a name, and the countdown ticks in days, hours, minutes and seconds. Without a time it counts to midnight at the start of that day, so "Christmas" means the moment 25 December begins. Share countdown copies a link that opens the same countdown on any device. The quick buttons count down to Christmas, New Year, Easter, Valentine's Day, Halloween, the solstices and the days left in the year.

Leap years, daylight saving and time zones

A year is a leap year if it divides by 4, except century years, which must also divide by 400: 2024 and 2028 are leap years, 2000 was, 2100 will not be. A range that includes a 29 February counts it, so a year can be 366 days. Days are counted on the calendar in your own time zone, so the switch to and from summer time never adds or removes a day. Hours and minutes are shown as days × 24, which across a clock change is one hour off the wall-clock time. For dates before the Gregorian calendar was adopted locally — 1582 in much of Catholic Europe, 1752 in Britain and its colonies — the calculator uses the modern calendar backwards, which is consistent but not what people wrote at the time.

Days between dates in Excel or Google Sheets

With the start date in A1 and the end date in B1: =B1-A1 gives the days between them, =B1-A1+1 includes both ends, =NETWORKDAYS(A1,B1) counts Monday-to-Friday working days with both ends included, =NETWORKDAYS.INTL(A1,B1,7) uses a Friday–Saturday weekend, =DATEDIF(A1,B1,"m") gives whole months, and =TODAY()-A1 gives the days since a date. Use a spreadsheet when the same calculation has to run over hundreds of rows, and this page for a quick answer you can share.

Unix timestamps and date formats

A Unix timestamp is the number of seconds since 1 January 1970, 00:00 UTC. Ten digits are seconds, thirteen are milliseconds, which is what JavaScript uses; mixing them up is how a date ends up in 1970 or the year 55000. Systems that store it in a signed 32-bit number overflow on 19 January 2038. When you write dates for other people, use ISO 8601 — 2026-04-03 — because 03/04/2026 is 3 April in most of the world and 4 March in the United States. The format converter shows a date in all the common forms with a copy button for each.

Private, free and shareable

All calculations run in your browser; dates are never sent anywhere, which matters when they are a contract deadline, a notice period or a medical appointment. Once the page has loaded it works offline. The share link stores the dates and settings in the address itself, so nothing is saved on a server. For legal, financial or medical deadlines, use the number here as your working figure and have it confirmed by whoever is responsible, because rules on when a period starts and what happens on a holiday differ.

More time tools

Turn a birthday into a fullscreen party with the birthday countdown, keep several time zones on screen with the world clock wall, read a cron schedule in plain English with the cron explainer, or work out a percentage with the percentage calculator. Everything else is on the apps page.