Calculadora do dia da semana

Find what day of the week any date falls on, next/previous occurrence of a weekday, and count or list weekdays in a range with step-by-step solutions.

Your Input

Format: YYYY-MM-DD

Select a calculation type, enter your dates and weekday, then click Calculate to see results with step-by-step solutions.

Guia do usuário completo

O que é uma calculadora de dia da semana?

A day of week calculator finds which weekday (Monday–Sunday) any date falls on, the next or previous occurrence of a chosen weekday, and how many times (or which dates) a weekday appears in a date range. It uses the Gregorian calendar and handles leap years and varying month lengths.

Weekday index: 0=Monday … 6=Sunday  |  Weekdays Mon–Fri; weekends Sat–Sun

Use it for scheduling, planning recurring events, or checking if a date is a weekday or weekend.

Date Format

Use YYYY-MM-DD (e.g. 2025-02-15). Dates from year 1 to 9999 are supported.

Tipos de cálculo

Encontrar dia da semana

Enter any date to see which weekday it is and whether it's a weekday or weekend.

Próxima ocorrência

From a date, find the next occurrence of a chosen weekday (e.g. next Monday).

Ocorrência Anterior

From a date, find the previous occurrence of a chosen weekday.

Contar dias da semana

Count how many times a specific weekday appears in a date range; includes chart.

Encontre todas as ocorrências

List all dates in a range that fall on a chosen weekday (e.g. all Mondays; up to 20 shown).

Como usar esta calculadora

  1. Select a calculation type (Find Day, Next/Previous Occurrence, Count Weekdays, or Find All Occurrences)
  2. Enter the required dates and choose a weekday where needed
  3. Click 'Calculate' to see the result
  4. Review the main result, detail card (weekday/weekend), occurrences list, and step-by-step solution
  5. Use the chart when counting weekdays for a visual breakdown
  6. Click 'Reset' to set all dates to today and clear results

Compreendendo seus resultados

Main result

The weekday name, result date, or count—depending on the mode. The subtitle shows the date or a short description.

Detail card

For Find Day of Week: indicates whether the date is a Weekday (Mon–Fri) or Weekend (Sat–Sun).

Occurrences list

For Find All Occurrences: lists the dates in the range that fall on the chosen weekday (up to 20).

Compreendendo os dias da semana

The calculator uses weekday index 0=Monday through 6=Sunday. Weekdays are Monday–Friday; weekends are Saturday and Sunday.

  • 0 = segunda-feira
  • 1 = terça-feira
  • 2 = quarta-feira
  • 3 = quinta-feira
  • 4 = sexta-feira
  • 5 = sábado
  • 6 = Domingo

Notas importantes

  • Uses Gregorian calendar; leap years and varying month lengths are handled.
  • Weekday index: 0=Monday … 6=Sunday. Weekdays Mon–Fri; weekends Sat–Sun.
  • Dates must be between year 1 and 9999. Use YYYY-MM-DD format.

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