Days Between Dates Calculator

How to Use the Days Between Dates Calculator

Almost every deadline that matters is expressed in business days, and almost nobody can count them reliably by hand past about a fortnight. This page walks the range day by day, so the answer is exact rather than estimated from an average week.

1. Enter the two dates. Either order works. The count runs from the start date up to but not including the end date, with the inclusive figure shown alongside.
2. Set which days are the weekend. Saturday and Sunday is the default, but Friday and Saturday is standard across much of the Middle East, and some workplaces treat only Sunday as non-working.
3. Paste in your holidays. One date per entry as YYYY-MM-DD, separated by commas or spaces. Anything outside the range is ignored, as is anything that already falls on a weekend.
4. Read the business-day figure. That is what a contract, a notice period or a shipping estimate almost always means when it says 'days'.

Everything runs locally at midnight UTC. No dates are transmitted and none are stored.

How the Count Is Made

There is a closed-form shortcut using whole weeks, and this calculator deliberately does not use it. Walking the range is exact under every weekend definition and never needs a special case for the ragged days at each end.

The rule about weekend holidays matters more than it sounds. A public holiday falling on a Saturday is not a working day lost, so deducting it would double-count and understate your business days. Where an observed day in lieu is granted on the following Monday, enter that Monday instead.

Note also that the two counts at each end behave differently. The start date is always counted and the end date never is, which is the standard half-open convention and the reason the inclusive figure is always exactly one larger.

Example

Worked example one: 5 January 2026 to 25 December 2026. That is 354 calendar days, or 355 counting both ends. Divided by seven it is 50.571 weeks — 50 whole weeks and 4 days.

Walking the range gives 50 Saturdays and 50 Sundays, exactly 100 weekend days, leaving 254 working days. The symmetry is a consequence of the start date being a Monday and the end date a Friday: the range holds a whole number of weeks plus four weekdays.

Now the holidays. Seven US federal holidays fall inside the range on weekdays — 19 January, 16 February, 25 May, 3 July, 7 September, and 26 and 27 November. Deducting them gives 247 business days, which is the figure a contract would mean.

Worked example two: why the shortcut fails. The tempting method is to multiply. Fifty-and-a-half weeks times five working days gives 252.9, so roughly 253 — three days out from the true 254 before holidays, and it would be further out for a range that started on a Saturday.

The error comes entirely from the ragged ends. Fifty whole weeks contribute exactly 250 working days, and the remaining four days — Monday to Thursday of the final part week — contribute four more, not 4 × 5/7 = 2.86. Whether those trailing days are weekdays or weekend days depends on which weekday you started on, and no average captures it.

Business Days Are the Figure That Binds

The business-day figure is the one to act on, because it is what deadlines are written in. 'Payment within 30 days' and 'payment within 30 business days' are six weeks apart in practice, and the difference is entirely invisible until somebody counts.

Holidays are where local knowledge beats any calculator. Federal, state, regional and company holidays all differ, and a supplier in one country will not observe yours. When a deadline spans a border, count it against the calendar of whoever has to act, not your own.

The weekend setting is not a nicety. A Friday-Saturday weekend shifts every business-day count in a range, and assuming Saturday-Sunday when dealing with much of the Middle East produces answers that are consistently wrong by a day or two per fortnight.

December is the case worth checking manually every year. Between public holidays, days in lieu and shutdown periods, the last fortnight of the year contains far fewer genuine working days than the calendar suggests, and deadlines set in November routinely land somewhere nobody intended.

For the same range expressed as years and months rather than as a count, the date difference calculator gives the calendar breakdown, and the age calculator does the same from a birth date.

Five Things a Count Cannot Know

Five things a business-day count cannot know.

Which holidays apply. There is no universal list — the United States has federal holidays that many private employers ignore, the United Kingdom has different bank holidays in each nation, and most countries have regional days besides. The list is yours to supply because only you know it.

Days in lieu. When a holiday falls on a weekend, many jurisdictions grant the following Monday off instead. This calculator ignores the weekend date, correctly, but it cannot invent the Monday — enter the observed day rather than the nominal one.

Half days and shutdowns. Christmas Eve, New Year's Eve and the afternoon before a long weekend are widely treated as non-working without appearing on any holiday list. Whole-company shutdown weeks are the same problem at a larger scale.

When the clock starts. Legal and contractual periods often begin on the day after service or receipt rather than on the day itself, and some specify clear days, which excludes both ends. The wording of the clause governs, not the arithmetic.

Whether the count is even in days. Some agreements run in months or in weeks rather than days, and a month there means a calendar month — from the 15th to the 15th — rather than thirty days. Converting one into the other before checking a deadline introduces an error of a day or two in either direction.

Where the wording says months, count months; the date difference calculator does that properly, and this page is for the ones written in days.

What counts as delivery. A courier's 'three business days' may start from despatch, from collection or from the next working day after the order, and the cut-off time on the first day decides which. The count is easy; the start point is the part worth reading carefully.