Work out the calendar and working days between two dates, or add and subtract days from any date: deadlines, notice periods, returns and due dates in an instant.
We count the elapsed days (end date minus start date): the start day is not counted and the end day is. If you swap the dates round, we use the absolute value.
Working days run Monday to Friday, without deducting bank holidays, which vary by nation. The calculation uses UTC dates, so the clock changes (DST) do not affect it.
Calendar days, working days and business days are not the same: here is the difference that decides whether you meet a deadline
Calendar days are every day on the calendar, including Saturdays, Sundays and bank holidays. This is the usual way of counting consumer deadlines (the 14-day cooling-off period for an online purchase is in calendar days) and many notice periods. This calculator counts the elapsed days: end date minus start date, not counting the starting day and counting the last.
A working day, in everyday and employment use, normally means Monday to Friday. A business day, in many official and banking deadlines, also excludes bank holidays. This calculator counts working days as Monday to Friday and does not deduct bank holidays, because the bank-holiday calendar differs across England & Wales, Scotland and Northern Ireland.
If a public body (such as HMRC or a tribunal) gives you a deadline in working days, weekends do not count, and many bodies also exclude bank holidays. If the deadline is in calendar days, every day counts; and where a deadline is set “date to date” (for example one calendar month), it runs to the corresponding day of the next month. When a final day falls on a weekend or bank holiday, deadlines are usually treated as ending on the next working day. Always check the letter or notice for the exact rule that applies.
Every four years February has 29 days (except centenary years not divisible by 400: 2100 will not be a leap year, 2400 will). A deadline that crosses 29 February of a leap year such as 2028 has one more day than it appears to. The date engine behind this calculator handles leap years automatically, with nothing for you to do.
We answer the most common questions about deadlines, working days and notice periods
Counting days seems trivial until a deadline really matters: the notice period before leaving a job, the 14 calendar days to return an online purchase, the 30 days to appeal an HMRC decision, or the days of leave you are owed between two dates. This days between dates calculator solves the two typical problems: measuring the exact distance between two dates (in calendar days, working days, weeks and months) and projecting a future or past date by adding or subtracting days, skipping weekends too.
The costliest mistake is usually not arithmetic but the type of day: confusing calendar days with working days can shorten or lengthen a deadline by several days. That is why the result always shows both figures, and below we explain which convention each body uses.
For official deadlines expressed in working days, the general rule is that weekends are excluded, and many bodies also exclude bank holidays. In other words, in business terms a Saturday is not a working day, even though colloquially someone might count it. If the deadline is expressed in calendar days, every day counts without exception, and where the final day is a weekend or bank holiday the deadline is usually treated as ending on the next working day. Some legal time limits are set “date to date” instead — for example an employment tribunal claim is generally brought within three months less one day of the event. Our working days (Monday to Friday) are a good approximation of business days, but remember we do not deduct bank holidays: these vary by nation and you should subtract them according to your local calendar.
The duration and type of days for each deadline depend on the specific rules or your contract: use the table as a guide and always check the document that sets your deadline.
A notice period when resigning is usually counted in calendar days (or in whole weeks or months), unless your contract says otherwise. In practice: if you give notice on the 1st with a 15-day period, your commitment runs out on the 16th (15 days elapsed). The statutory minimum notice an employee must give is one week once they have been employed for a month or more, but many contracts require longer for senior or technical roles (a month, or three months). If your contract expresses notice in working days, switch on the “working days only” option in add/subtract mode and adjust for any local bank holidays. Failing to give the required notice can entitle the employer to recover pay for the days not worked.
Two common traps in home-made date sums are leap years and the clock change. The first is solved by using the real calendar: 2028 will have a 29 February and the calculator counts it, just as it knows 2100 will not be a leap year. The second is more subtle: if you calculate with local time, the night of the clock change lasts 23 or 25 hours and a naive subtraction can give a day too few or too many. This calculator works with pure UTC dates at midnight, so every day lasts exactly 24 hours for counting purposes and the result is always a whole, correct number of days.
Note: This calculator is a guide for counting days. Working days are counted Monday to Friday without deducting bank holidays (which vary across England & Wales, Scotland and Northern Ireland), so they are not exactly the same as the business days of a specific procedure. For official or legal deadlines with real consequences, confirm the count with the relevant body or a professional.
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