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How many working days in year 1990?

Here is the detail of the calculation:

Because 1990 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 1990.

Here is the list of these 9 public holidays:

1. Solenidade da Santa Mãe de Deus : понедельник, 1 январь, 1990
2. Sexta-Feira Santa : пятница, 13 апрель, 1990
3. Dia da Liberdade : среда, 25 апрель, 1990
4. Dia do Trabalhador : вторник, 1 май, 1990
5. Corpo de Deus : четверг, 14 июнь, 1990
6. Assunção de Nossa Senhora : среда, 15 август, 1990
7. Implantação da República : пятница, 5 октябрь, 1990
8. Todos os Santos : четверг, 1 ноябрь, 1990
9. Natal : вторник, 25 декабрь, 1990

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

1. Páscoa : воскресенье, 15 апрель, 1990
2. Dia de Portugal : воскресенье, 10 июнь, 1990
3. Restauração da Independência : суббота, 1 декабрь, 1990
4. Dia da Imaculada Conceição : суббота, 8 декабрь, 1990