Define a period

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How many working days in year 1991?

Here is the detail of the calculation:

Because 1991 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 9 public holidays that do not fall during a weekend and we obtain 252 working days in 1991.

Here is the list of these 9 public holidays:

1. Solenidade da Santa Mãe de Deus : Tuesday, 1 January, 1991
2. Sexta-Feira Santa : Friday, 29 March, 1991
3. Dia da Liberdade : Thursday, 25 April, 1991
4. Dia do Trabalhador : Wednesday, 1 May, 1991
5. Corpo de Deus : Thursday, 30 May, 1991
6. Dia de Portugal : Monday, 10 June, 1991
7. Assunção de Nossa Senhora : Thursday, 15 August, 1991
8. Todos os Santos : Friday, 1 November, 1991
9. Natal : Wednesday, 25 December, 1991

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

1. Páscoa : Sunday, 31 March, 1991
2. Implantação da República : Saturday, 5 October, 1991
3. Restauração da Independência : Sunday, 1 December, 1991
4. Dia da Imaculada Conceição : Sunday, 8 December, 1991