Define a period

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How many working days in year 1973?

Here is the detail of the calculation:

Because 1973 is not a leap year, it has 365 days.

Let's remove 52 saturdays and 52 sundays. It remains 261 days.

Now, let's remove 10 public holidays that do not fall during a weekend and we obtain 251 working days in 1973.

Here is the list of these 10 public holidays:

1. Solenidade da Santa Mãe de Deus : Monday, 1 January, 1973
2. Sexta-Feira Santa : Friday, 20 April, 1973
3. Dia da Liberdade : Wednesday, 25 April, 1973
4. Dia do Trabalhador : Tuesday, 1 May, 1973
5. Dia dos Açores : Monday, 11 June, 1973
6. Corpo de Deus : Thursday, 21 June, 1973
7. Assunção de Nossa Senhora : Wednesday, 15 August, 1973
8. Implantação da República : Friday, 5 October, 1973
9. Todos os Santos : Thursday, 1 November, 1973
10. Natal : Tuesday, 25 December, 1973

And here are the 4 public holidays falling on a weekend:

1. Páscoa : Sunday, 22 April, 1973
2. Dia de Portugal : Sunday, 10 June, 1973
3. Restauração da Independência : Saturday, 1 December, 1973
4. Dia da Imaculada Conceição : Saturday, 8 December, 1973