Define a period

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How many working days in year 1980?

Here is the detail of the calculation:

Because 1980 is a leap year, it has 366 days.

Let's remove 52 saturdays and 52 sundays. It remains 262 days.

Now, let's remove 12 public holidays that do not fall during a weekend and we obtain 250 working days in 1980.

Here is the list of these 12 public holidays:

1. Año Nuevo : Tuesday, 1 January, 1980
2. Jueves Santo : Thursday, 3 April, 1980
3. Viernes Santo : Friday, 4 April, 1980
4. Día del Trabajo : Thursday, 1 May, 1980
5. Día de la Fuerza Aérea : Wednesday, 23 July, 1980
6. Día de la Independencia : Monday, 28 July, 1980
7. Día de la Independencia : Tuesday, 29 July, 1980
8. Batalla de Junin : Wednesday, 6 August, 1980
9. Combate de Angamos : Wednesday, 8 October, 1980
10. Día de la Inmaculada Concepción : Monday, 8 December, 1980
11. Batalla de Ayacucho : Tuesday, 9 December, 1980
12. Navidad : Thursday, 25 December, 1980

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

1. Batalla de Arica y Día de la Bandera : Saturday, 7 June, 1980
2. Día de San Pedro y San Pablo : Sunday, 29 June, 1980
3. Día de Santa Rosa de Lima : Saturday, 30 August, 1980
4. Día de Todos los Santos : Saturday, 1 November, 1980