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 10 public holidays that do not fall during a weekend and we obtain 252 working days in 1980.

Here is the list of these 10 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 del Ejército : Monday, 30 June, 1980
6. Día de la Independencia : Monday, 15 September, 1980
7. Día de la Revolución : Monday, 20 October, 1980
8. Noche Buena : Wednesday, 24 December, 1980
9. Navidad : Thursday, 25 December, 1980
10. Víspera de Año Nuevo : Wednesday, 31 December, 1980

And here are the 2 public holidays falling on a weekend:

1. Sábado Santo : Saturday, 5 April, 1980
2. Día de Todos los Santos : Saturday, 1 November, 1980