Project Deadline Countdown Calculator
Count the calendar days, working days and working hours left until a project deadline. Tick the days you actually work, paste in any holidays, and the calculator works the rest out. There is a one-click button for the standard England and Wales 2026 bank holidays if you need them.
Explain like I'm 5 (what even is this calculator?)
You give it a deadline date. It counts how many days are left. It also counts only the days you actually work, so weekends and holidays do not get in the way. Then it tells you how many hours of real work that adds up to, so you can see whether the plan fits or not.
Work out the countdown
Result
Heads up: the deadline is in the past. The numbers below are how far past, not how far ahead.
Heads up: you have not ticked any working days, so the working-day and working-hour totals are zero by definition.
- Calendar days 0
- Working days 0
- Working hours 0
Mini-calendar
Prove it (show the working)
Enter a deadline above and press Calculate to see the working.
Useful? Save this calculator: press Ctrl + D to bookmark it.
Why working days matter more than calendar days
Calendar days are tidy. The number ticks down, day by day, regardless of whether anyone is at a desk. That tidiness is also why they mislead. A two-week deadline announced on a Friday looks generous on the calendar (14 days) but is closer to nine working days once you remove the two weekends, and might be eight if there is a bank holiday in there. Counting in calendar days when you should be counting in working days is one of the reliable ways a project quietly slips. The calculator exists to make the gap obvious before you commit to a date.
The other thing calendar-day arithmetic hides is unequal months. February and August both have public holidays attached at the end (in much of Europe at least), so even if a six-week project always reads as 42 calendar days, the working-day count varies by where in the year you start. Sliding the same plan from May to July can quietly cost you three working days if a couple of bank holidays land inside the new window.
Who this is for
Project managers running internal stand-ups, freelancers committing to a delivery date, students working backwards from an essay deadline, contractors estimating a job, anyone who keeps getting blindsided by a bank holiday. The maths is not complicated, but doing it in your head while you are on a call is fiddly. Pasting a list of dates and tweaking a checkbox is faster and harder to get wrong.
How the working-day rule is applied
Walk forward one day at a time, starting the day after the start date and finishing on the deadline. For each day, ask two questions. Is this weekday in the set the user ticked? And is this date in the holidays list? A day counts only if the answer to the first is yes and the answer to the second is no. The start day is excluded so that "today is the deadline" reads as zero working days remaining, which is what most people mean by it. The deadline day is included, because if your work is due by close of business on Friday, you probably do mean to work on Friday.
Holidays that fall on a weekend, or on a weekday you have not ticked, are ignored. They cannot subtract a working day from the count because the day was never going to be a working day in the first place. This is the most common quiet bug in homemade spreadsheets that try to do the same thing: a list of UK bank holidays that double-counts the substitute days.
Common mistakes
The biggest mistake is forgetting to add holidays at all. The calendar-vs-working gap people remember is weekends, but a year with eight bank holidays plus annual leave loses you nearly four working weeks on top of the two weekends a month. If a project plan was costed on calendar days, the real working budget is significantly tighter than it looks.
The second common mistake is mixing up date formats. UK readers write 03/04/2026 and mean 3 April. US readers write 03/04/2026 and mean 4 March. The calculator uses DD/MM/YYYY for the slash format because that is the British convention this site is written in, and accepts the unambiguous YYYY-MM-DD as the alternative. If you are sharing a list with collaborators in another country, paste the ISO format and avoid the argument.
Third, watch for stretched weeks at the start and end of a project. A "two-month" project starting on the last working day of a month and ending on the first working day of the month two months later contains roughly 41 working days, not 44. The calculator handles this fine, but it is the sort of thing that catches you out if you mentally round to four weeks per month.
Working days, business days, trading days
For project planning these terms are mostly interchangeable, but it is worth knowing the distinction. Working days and business days both refer to the days a normal office is open: weekdays minus public holidays. Trading days are a financial-markets concept and refer to the days a particular exchange is open, which can differ from public holidays (Good Friday is a market holiday in the US even though it is not a federal holiday, and individual markets observe their own anniversaries). If you are working with a finance team, ask which one they mean before you assume.
Edge cases
If you set the start date and the deadline to the same date, the count is zero working days. If you set the deadline before the start, the calculator reports the gap as a negative number, with the wording flipped to "deadline was X working days ago". If you untick every day of the week, the working-day total is zero by definition and the calculator says so rather than dividing by anything. A holiday on the deadline itself is excluded, so a project due on Christmas Day with Christmas Day in the holidays list comes out one working day shorter than the same project due on Christmas Eve.
Related calculators
Working days remaining is one number. These fill out the picture.
Frequently asked questions
Why is the working-day count smaller than calendar days?
Working days exclude any day whose weekday you have not ticked, plus any date that appears in your holidays list. Most people leave Monday to Friday ticked and paste in their public holidays, so weekends and bank holidays drop out and the working-day total is roughly five sevenths of the calendar-day total, minus a few for holidays. The calculator shows both numbers so you can see the gap and plan against the one that matters.
What date formats does the holidays box accept?
One date per line, in either YYYY-MM-DD (the ISO format, like 2026-04-03) or DD/MM/YYYY (the UK convention, like 03/04/2026). Lines that do not parse as dates are listed in the prove-it panel so you can fix typos. Blank lines are ignored, and duplicates are deduped.
Are time zones a problem if I am working with a remote team?
Not for this calculator. Every date is treated as a local calendar date with no time component, so 30 April is 30 April regardless of where you sit. The standard browser-date trap, where 2026-04-30 silently parses as 2026-05-01 in some time zones, is avoided by constructing the date with explicit year, month and day in the user's local zone.
Can I save the result?
There is no account or saved-state feature. Use the bookmark prompt at the bottom of the calculator to keep the page handy, screenshot the result panel, or copy the summary line into your project notes. Everything happens in your browser and nothing is uploaded.
What is the difference between working days, business days and trading days?
Working days and business days are usually used interchangeably and mean the days a normal office is open, typically Monday to Friday minus public holidays. Trading days are specific to financial markets and exclude additional days when an exchange is closed (some half-day closures, market holidays that are not public holidays, and so on). For ordinary project planning, working days is what you want, and that is what this calculator gives you.