Working Days Calculator UK

Guides

Longer reads that go beyond the calculators — the rules behind UK working days, bank holidays, contracts, and payroll, written in plain English for the people who have to apply them.

Who these guides are for

The calculators on this site give you a date or a count in seconds. These guides explain the rules behind those numbers — the kind of thing you need when a deadline is contested, a payslip is queried, or a contract has to be read carefully rather than skimmed. They are written for the people who deal with this in their day job: HR and payroll teams, paralegals and solicitors, finance and accounts-payable staff, and project managers planning around the bank holiday clusters.

Each guide sticks to plain English and concentrates on the practical question rather than the theory. Where the law or official guidance matters, we point to the primary source — principally gov.uk and ACAS — so you can check the position yourself rather than take our word for it. None of this is a substitute for professional advice on a specific case, but it should help you ask the right questions.

We review the guides at least once a year, and sooner when the law or guidance they rely on changes — as it did for irregular-hours and part-year workers in April 2024. Each guide shows when it was last reviewed at the top.

Questions these guides answer

Between them, the three guides cover the questions that come up again and again:

Prefer to just get an answer?

If you already know the rule and only need the date, head straight for the tools: the working days calculator to add or subtract working days, the business days calculator for contract deadlines, the days-between-dates tool, or the bank holiday pages for the dates themselves. The guides are here for when the answer needs more than a number.