Date calculator
Three date jobs in one place: the gap between two dates, a date plus or minus days, and the working-day count with UK bank holidays handled.
Guide
How to use it
- Pick the mode: Days between, Add or subtract, or Working days.
- For gaps, choose inclusive or exclusive counting, the toggle explains which is which, and contracts care.
- For deadlines, add days to a start date and get the weekday too, "90 days from signature" lands somewhere specific.
- Working days counts Monday to Friday minus England and Wales bank holidays.
Examples
Date arithmetic in the wild
Consumer returns windows run in calendar days from delivery. Add 14 to the delivery date, that weekday is your last safe posting day.
Schengen’s 90-in-180 rule starts with simple gap counting. This does the 90, the rolling window bookkeeping is on you (or your passport stamps).
"One month’s notice" ends on the corresponding date next month, but "20 working days" needs the working-day counter, they differ by more than people expect around Easter.
Method
How it works
Gap counting subtracts calendar dates with a midday anchor so British Summer Time transitions cannot produce off-by-one errors. Whole-month figures use calendar months (the 15th to the 15th), not 30-day approximations.
Working days iterate the actual calendar, skipping weekends and the built-in England and Wales bank holiday list (2025 to 2027, an editable constant flagged for annual review).
FAQ
Frequently asked questions
Inclusive or exclusive, which do I want?
Depends what you are measuring: nights away is exclusive (Friday to Monday is 3), days present is inclusive (4). Deadlines usually mean exclusive, day counting from tomorrow.
Do the calculations handle leap years?
Yes, real calendar arithmetic throughout, 29 February exists in this tool exactly when it exists in life.
Why did my "between" months look odd?
Whole months count anniversary-to-anniversary: 31 January to 1 March is one month (and a day), not two. It matches how contracts read, not how counting fingers work.
Which bank holidays are excluded?
England and Wales. Scotland and Northern Ireland have additional or different days (2 January, St Patrick’s, the Twelfth) that this count does not remove.
Can I count backwards, like 28 days before a date?
Yes, the add/subtract mode subtracts too, useful for "submit 28 days before the hearing" reverse deadlines.
Is anything looked up online?
No, the holiday list ships with the page and everything computes locally.
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