Add Business Days to a Date
Calculate the due date after a given number of business days.
Enter a start date and a number of business days to calculate the due date.
How is this result calculated?
Starting from the start date, the calculator moves forward day by day and only counts weekdays (Monday to Friday), skipping French legal public holidays if that option is enabled, until it has counted the requested number of business days. The date of the last counted business day is the due date returned.
Movable holidays (Easter Monday, Ascension Day, Whit Monday) are calculated from the date of Easter for each year involved, itself determined with the Meeus/Jones/Butcher algorithm — which keeps the calculation accurate for any year, including when the delay spans several consecutive years.
Frequently asked questions
What's the difference with the "add days to a date" calculator?+
This calculator only counts business days (Monday to Friday, excluding French public holidays if that option is enabled). The /ajouter-jours-date calculator instead adds a raw number of calendar days, weekends and holidays included. Use this one for a delay expressed "in business days" (a delivery deadline, a legal deadline...), and /ajouter-jours-date for a simple calendar shift.
How is the start date treated?+
If "include the start date" is enabled and the start date is itself a business day, it counts as day 1 of the count. If it's disabled, the start date is never counted: the business-day count always begins on the following day.
Which public holidays are taken into account?+
The 11 French legal public holidays: the 8 fixed ones (New Year's Day, Labour Day, Victory in Europe Day, Bastille Day, Assumption Day, All Saints' Day, Armistice Day, Christmas Day) and the 3 movable ones that depend on the date of Easter (Easter Monday, Ascension Day, Whit Monday). They are only removed from the count if "exclude French public holidays" is enabled.
What happens if the delay spans several years?+
The calculation stays accurate with no time limit: public holidays are automatically recalculated for every calendar year the count runs through, including movable holidays whose date changes every year.
An example use case?+
A shop advertises delivery "within 20 business days" from the order date: this calculator gives you the resulting due date directly, public holidays deducted if needed.