Working Days Calculator

How to use the working days calculator

Enter the date the clock starts and the date it stops, and the tool counts the Monday-to-Friday days in between. Both boxes are native date fields, so type them or pick them from your device’s calendar. The loaded example runs 1 January to 25 December 2026, which is there to show the tool working — replace either date and the numbers update as you type.

The order does not matter either: enter the later date first and the calculator sorts the pair before counting, rather than returning zero or a negative.

The count includes the start date but stops before the end date, which is how notice periods, invoice terms, and turnaround windows are normally written. If your question counts both endpoints — the first day and the last day of a leave request, say — add one working day when the end date is itself a weekday.

This is the count people need when a deadline is written in business days rather than calendar days, and the two are far enough apart to cause real trouble.

A 30-day notice period, a net-30 invoice, a 10-business-day bank hold, an SLA promising a fix within five working days, a PTO request measured against an accrual balance, or a project plan that only has capacity Monday through Friday — all of them ignore weekends, and all of them go wrong if you count calendar days by mistake.

One honest limitation: public holidays are not deducted. Holidays differ by country, by state, and by employer, and no calculator can know which ones your office closes for, so this tool counts weekdays only and leaves the subtraction to you.

The United States has 11 federal holidays set by 5 U.S.C. 6103 and published by the Office of Personnel Management, and those bind federal agencies rather than private employers, who are free to observe more, fewer, or different days. England and Wales follow a separate list of bank holidays published at gov.uk, with Scotland and Northern Ireland different again.

The table below breaks 2026 down month by month so you can see exactly which weekdays a US federal office loses inside your span.

What do the full weeks and weekend days tell you?

Read the supporting lines as a sanity check on the headline. Calendar days is the raw span, weekend days is every Saturday and Sunday inside it, and working days plus weekend days always equal the calendar total — if they do not, one of your dates is not the one you meant.

Full weeks tells you how many complete seven-day blocks the span contains, which is where the bulk of the arithmetic comes from, since every run of seven consecutive days contains exactly five weekdays no matter which day it starts on. Only the leftover days at the end need individual inspection, and there are never more than six of them, which is why the calculation is instant even across spans measured in decades.

The formula, worked line by line

Every seven consecutive days contain exactly five weekdays, whichever day of the week you start on. That single fact turns what looks like a day-by-day walk through a span into one multiplication plus a very short remainder, and it is why the answer appears instantly even for a span measured in decades.

Only the leftover days after the last whole week need to be inspected individually, and there are never more than six of them. That is the whole algorithm: divide by seven, multiply the quotient by five, then check the handful of days at the end. Nothing about it depends on which month or year the span sits in, which is why leap years, month lengths, and daylight-saving transitions have no effect on the result at all.

span = days from the start date up to (not including) the end date
full weeks = span ÷ 7, rounded down
working days = full weeks × 5 + each leftover day that is not a Saturday or Sunday
weekend days = span − working days

Now the part the calculator leaves to you. Ten of the 11 US federal holidays are observed on a weekday inside that window: everything from New Year's Day through Thanksgiving, including Independence Day, which falls on a Saturday in 2026 and is therefore observed on Friday, 3 July under the in-lieu rule. The eleventh, Christmas Day, is the end date itself, which the count excludes.

A federal office closing for all of them would therefore work 256 − 10 = 246 days across the span. Your own figure will differ: swap in the days your employer actually closes, and remember that private employers in the United States are not required to observe any federal holiday, while other countries publish entirely separate lists.

Working days in a whole year

Across a whole calendar year the same arithmetic gives a narrow range. A common year is 52 weeks plus one day, so it holds 260 weekdays plus that extra day if it happens to be a weekday. A leap year is 52 weeks plus two days, so it can reach 262 or fall back to 260 when both spare days land on the weekend.

Take the 11 federal holidays off 2026 and a federal office works 250 days, which is the figure the last row of the table above lands on, and the one worth using when you are budgeting capacity for a year rather than a sprint.

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