Working Days Calculator

“Ten working days” has four answers

Monday the 5th to Friday the 16th, weekends off. Counting both ends gives ten. Counting the end but not the start gives nine. Counting the start but not the end gives nine. Counting neither gives eight. Every one of those is correct and they answer different questions.

So two people using two spreadsheets get two dates, both are certain, and neither wrote down which convention they used, because neither knew there was a choice to write down. The argument that follows looks like an argument about a date and is really an argument about a word.

This tool never shows one number. It shows all four with the sentence each one is the right answer to, so the question becomes which sentence you meant, which is a question a person can actually settle.

The second choice nobody writes down is whose calendar

A working-day count with no holidays in it is not a working-day count. It is a weekday count, and over a full year the two differ by ten or eleven days. Most calculators quietly ship one country’s public holidays and present the result as though it were your company’s calendar.

Nothing is assumed here. If you give no holidays, the tool says in as many words that it counted weekdays, and shows you what the difference would have been. The US federal list is offered as a starting point and labeled as exactly that: most employers close on some of those days and not others, and on days that are not on it at all.

A holiday list that stops at the end of a year

This is the one that does real damage quietly. You load the holidays for this year, and some of the spans in your file run into next year. Those spans get counted with no holidays at all, which makes them longer than the rest, and nothing on the page looks wrong. The two halves of your report are no longer comparable and nobody can see why.

The tool checks which years your data touches against which years your holiday list covers, and says so when they differ.

The holiday that lands on a weekend

The 4th of July 2026 is a Saturday. Whether your offices close on Friday the 3rd is a policy somebody decided once and probably did not write down, and it moves every count that crosses it. You can leave the holiday where it fell, move it to the nearest working day, or always move it forward, and the tool says which it did and what it cost.

When two holidays end up on the same date after moving, that date is one day off and not two. It is the sort of thing that removes a working day which actually exists, once a year, in a way nobody ever traces back.

The dates in your file may not mean what they look like

03/04/2026 is either the 3rd of April or the 4th of March, and the two give different counts. When every date in a column reads correctly both ways, nothing in the file can settle it, and this tool says so rather than choosing. When one row proves day-first and another proves month-first, the column holds two formats at once and some of the counts are wrong whichever way you read it.

What this does not do

It counts days against a calendar you supply. It knows nothing about notice periods, statutory deadlines, or what any of these spans mean, and it is not advice about any of them. A count is an input to a decision somebody else makes with information this tool does not have.

For counting days lost to absence with the reporting that goes around it, the Absence Analyzer is the tool. For the dates themselves being in three different formats in one column, start with the Employee Data Cleaner.