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How many working days in year 1977?

Here is the detail of the calculation:

Because 1977 is not a leap year, it has 365 days.

Let's remove 53 saturdays and 52 sundays. It remains 260 days.

Now, let's remove 9 public holidays that do not fall during a weekend and we obtain 251 working days in 1977.

Here is the list of these 9 public holidays:

1. Sexta-Feira Santa : пятница, 8 апрель, 1977
2. Dia da Liberdade : понедельник, 25 апрель, 1977
3. Corpo de Deus : четверг, 9 июнь, 1977
4. Dia de Portugal : пятница, 10 июнь, 1977
5. Assunção de Nossa Senhora : понедельник, 15 август, 1977
6. Implantação da República : среда, 5 октябрь, 1977
7. Todos os Santos : вторник, 1 ноябрь, 1977
8. Restauração da Independência : четверг, 1 декабрь, 1977
9. Dia da Imaculada Conceição : четверг, 8 декабрь, 1977

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

1. Solenidade da Santa Mãe de Deus : суббота, 1 январь, 1977
2. Páscoa : воскресенье, 10 апрель, 1977
3. Dia do Trabalhador : воскресенье, 1 май, 1977
4. Natal : воскресенье, 25 декабрь, 1977