Business days calculator: add working days to a date

The deadline N business days after or before a start date, skipping weekends and the holidays you list, with the calendar days it spans.

Atualizado Exemplos verificados: 5

= 2026-09-29
One ISO date per line (YYYY-MM-DD), optionally followed by a name.
Mais opções
Only applies when the start date is itself a working day.
Experimentar
Deadline
Tuesday, 13 October 2026
Deadline: Tuesday, 13 October 2026
Dia da semana
Tuesday
Calendar days
14days
Weekend days skipped
4

10 working days after Tue 29 Sep 2026 is Tuesday, 13 October 2026 — 14 calendar days later, skipping 4 weekend days.

Working days to the deadline

10 working days: 29 Sep 2026 to 13 Oct 202610 working daysStartTue 29 Sep 2026DeadlineTue 13 Oct 2026

Calendar days in the span

14calendar days
Working days71.4%Weekend days28.6%
Day by day Linhas: 15
DateCounts as
Tue 29 Sep 2026Start (not counted)
Wed 30 Sep 2026Working day 1
Thu 1 Oct 2026Working day 2
Fri 2 Oct 2026Working day 3
Sat 3 Oct 2026Weekend
Sun 4 Oct 2026Weekend
Mon 5 Oct 2026Working day 4
Tue 6 Oct 2026Working day 5
Wed 7 Oct 2026Working day 6
Thu 8 Oct 2026Working day 7
Fri 9 Oct 2026Working day 8
Sat 10 Oct 2026Weekend
Sun 11 Oct 2026Weekend
Mon 12 Oct 2026Working day 9
Como é calculado S
  1. Rule

    Start counting on the day after Tue 29 Sep 2026; the start date itself is not counted.

    Weekend: Saturday and Sunday.

  2. Skip non-working days

    14 calendar days=10 working+4 weekend+0 holiday14\ \text{calendar days} = 10\ \text{working} + 4\ \text{weekend} + 0\ \text{holiday}
  3. Deadline

    Tuesday, 13 October 2026.

Sobre Business days calculator: add working days to a date

Counting starts on the day after the start date. Each day that is neither a weekend day nor a listed holiday counts as one working day, and the nth such day is the deadline; going backwards works the same way from the day before. This is the convention of Excel's WORKDAY functions and NumPy's busday_offset. A holiday that falls on a weekend is skipped once, not twice.

It is used for payment terms, statutory response times, service-level targets and delivery estimates. Five working days after Friday, 18 December 2026, with Christmas Day and New Year's Day listed, is Monday, 28 December, 10 calendar days later. England and Wales also have a bank holiday on 28 December 2026, the substitute day for Boxing Day; list it and the deadline moves to Tuesday, 29 December.

Public holidays differ by country and region, so none are assumed: paste your own, one ISO date per line.

Exemplos resolvidos

Five working days over Christmas

Start date
2026-12-18
Working days
5
Direction
After the start
Weekend
Sat–Sun
Holidays
2026-12-25 Christmas 2027-01-01 New Year
Deadline
2026-12-28
Dia da semana
Monday
Calendar days
10 days
Weekend days skipped
4
Holidays skipped
1
Holidays in the way
Christmas (Fri 25 Dec 2026)

Fonte de verificação: numpy.busday_offset('2026-12-18', 5, roll='backward', holidays=[...]) = 2026-12-28; skipped days counted by hand on a 2026 calendar

Starting on a Saturday

Start date
2026-01-17
Working days
1
Direction
After the start
Weekend
Sat–Sun
Deadline
2026-01-19
Dia da semana
Monday

Fonte de verificação: numpy.busday_offset('2026-01-17', 1, roll='backward') = 2026-01-19

Friday–Saturday weekend

Start date
2026-01-15
Working days
10
Direction
After the start
Weekend
Fri–Sat
Deadline
2026-01-29
Calendar days
14 days

Fonte de verificação: numpy.busday_offset('2026-01-15', 10, roll='backward', weekmask='1111001') = 2026-01-29

Ten working days back over New Year's Day

Start date
2026-01-15
Working days
10
Direction
Before the start
Weekend
Sat–Sun
Holidays
2026-01-01
Deadline
2025-12-31
Dia da semana
Wednesday
Holidays skipped
1

Fonte de verificação: numpy.busday_offset('2026-01-15', -10, roll='forward', holidays=['2026-01-01']) = 2025-12-31

Perguntas

How do I work out 10 business days from a date?

Count forward from the next day and skip weekends and public holidays. With no holidays in the way, 10 business days is two full working weeks, so from a weekday it lands on the same weekday 14 calendar days later: 10 business days after Thursday, 15 January 2026 is Thursday, 29 January. Each holiday on a weekday pushes the deadline one working day further.

Is the start date counted as a business day?

Not by default. The first working day is the day after the start, the same as Excel's WORKDAY, so 1 business day after a Monday is Tuesday. Some contracts and procedures count the start date as day 1; switch on that option and 10 working days from Thursday, 15 January 2026 ends on Wednesday, 28 January instead of Thursday, 29 January.

What if the start date falls on a weekend or holiday?

Counting still begins with the next working day, so the weekend adds nothing. 1 business day after Saturday, 17 January 2026 is Monday, 19 January, the same answer as from Friday, 16 January. With the start-date option on, a start that isn't a working day can't be day 1, and the calculator warns you.

How many working days are in a month?

Between 20 and 23 weekdays before public holidays. February has exactly 20 in a common year and 20 or 21 in a leap year; a 30-day month has 20 to 22 and a 31-day month 21 to 23, depending on the weekday it starts on. A year of 261 weekdays, as in 2026, averages 21.75 per month.

Qual é a precisão de “Business days calculator: add working days to a date”?

A precisão depende dos dados inseridos e das hipóteses do método. O cálculo decimal usa 50 algarismos significativos, mas estimativas, métodos numéricos e dados de origem podem ter menor precisão; o arredondamento exibido não elimina essas limitações. Exemplos resolvidos verificados com fontes independentes: 5. Por exemplo, “Five working days over Christmas” é verificado com numpy.busday_offset('2026-12-18', 5, roll='backward', holidays=[...]) = 2026-12-28; skipped days counted by hand on a 2026 calendar.

De onde vem o método?

Microsoft Excel WORKDAY.INTL function (same convention: the start date is not counted); NumPy busday_offset.

Sobre esta calculadora

deadline=the n-th day after the start that is neither a weekend day nor a holiday\text{deadline} = \text{the } n\text{-th day after the start that is neither a weekend day nor a holiday}

Fontes

  1. Microsoft Excel WORKDAY.INTL function (same convention: the start date is not counted)
  2. NumPy busday_offset

Verificado com as referências

Esta calculadora inclui 5 exemplos resolvidos com respostas de fontes independentes. Eles fazem parte do conjunto de testes e você também pode executá-los aqui.

Calculadoras relacionadas