Add Working Days to a Date
Pick a start date and a number of working days. The calculator skips weekends and UK bank holidays and tells you where you land.
Use a negative number to count backwards.
Enter a date and a number of working days.
How “add working days” is calculated
Adding N working days means counting forward N weekdays from the start date, skipping Saturday, Sunday, and any UK bank holiday applicable to the selected region. The start date itself is not counted, so adding one to a Friday produces the following Monday.
Easter and Christmas are the two big clusters that push results further out than you might expect. Spring and August bank holidays also matter — three of the eight English bank holidays sit on Mondays, so a short add can absorb two non-working days back to back.
Negative numbers count backwards. Subtracting one working day from a Monday gives the previous Friday (assuming neither is a bank holiday).
Worked examples
Each answer below is produced by the calculator above — change the region and watch the Scottish example move.
Probation review at 20 working days
A new starter joins on Monday 6 July 2026 and HR sets a first review 20 working days in.
- Question
- When does the review fall?
- Answer
- Monday, 3 August 2026
- Why
- Twenty working days is four working weeks once weekends are removed. No bank holidays fall in this stretch in England & Wales, so it lands cleanly four weeks on.
Same window, Scottish calendar
The same 20-working-day count, but for a Glasgow office starting Monday 27 July 2026 — the Scottish Summer bank holiday (3 August) sits inside the window.
- Question
- When does the review fall?
- Answer
- Tuesday, 25 August 2026
- Why
- Switching to Scotland adds the early-August Summer holiday, which England & Wales does not observe until the end of the month — so the deadline shifts a day later than the English calendar would give.
Subtract to find a notice start date
A contractual step must complete by Friday 18 December 2026 and needs 7 working days' notice.
- Question
- What is the last day to serve notice?
- Answer
- Wednesday, 9 December 2026
- Why
- Counting back 7 working days steps over the intervening weekends to give the latest date notice can be served and still leave a full seven working days.
Who uses this, and how
HR & employment
Probation reviews, notice periods, and return-to-work dates are routinely set in working days so a weekend never silently shortens or extends them. Adding working days from a start date gives a defensible, consistent deadline for both employee and employer.
Legal practice
Service of documents and responses to directions are usually counted in clear working days from the triggering event. Counting forward from the date of service — with the start day excluded — matches the way most rules and orders are drafted.
Payroll
Cut-off-to-payment timetables, BACS lead times, and corrections to a pay run are easier to track in working days. Adding the bank's standard processing days to a submission date shows the true date funds will reach employees.
Project management
Task durations on a programme are normally quoted in working days. Adding them to a start date — and subtracting to find the latest safe start — keeps a plan honest about the Easter, May, and Christmas clusters that compress delivery windows.
Frequently asked questions
How is "add 5 working days" interpreted?+
The result is the date that is 5 working days after the start date, skipping weekends and bank holidays. The start date itself is not counted — so adding 5 to a Monday lands on the following Monday (assuming no bank holidays in between).
Can I subtract working days?+
Yes. Enter a negative number in the working days field to count backwards from the start date. This is how you work out the latest date to start a task so it finishes by a fixed deadline.
Why is my result different from another calculator?+
The two most common reasons: (1) different region — Scotland and Northern Ireland have extra bank holidays; (2) a different definition of "working days" — some calculators include Saturdays or count the start date as day one. Check both settings.
Does the start date count as day zero or day one?+
Day zero. Counting begins on the next working day after the start date, which matches how most UK contracts and notice periods are written ("within X working days of" an event). If your rule counts the start date itself, add one fewer day.
What if the start date is a weekend or bank holiday?+
It still works. The start date is only a reference point; counting begins from the next working day either way. If you need the result to begin from the next working day on or after a weekend start, add the days as normal — the skipped weekend is already accounted for.
How do I add working days for a Scottish or Northern Irish deadline?+
Select the matching region before you calculate. A deadline under Scottish law should use the Scottish calendar (2nd January, St Andrew's Day, the early-August Summer holiday), and a Northern Ireland deadline should include St Patrick's Day and the Battle of the Boyne.
Can I add a large number of working days, like 90?+
Yes, there's no practical limit within the supported date range. Ninety working days is roughly eighteen calendar weeks once weekends and any bank holidays in the span are stripped out — useful for long-stop dates and probation periods quoted in working days.
Does "within 10 working days" include today?+
By the usual reading, no. The clock starts on the next working day, so a task notified on a Monday with a 10-working-day window is due two weeks on the Friday, assuming no bank holidays. If the wording is ambiguous, the safer course is to treat the earlier date as the deadline.
How do I find the latest start date to hit a fixed deadline?+
Enter the deadline as the start date and subtract the number of working days the task needs. The result is the last working day you can begin and still finish on time.