Define a period

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How many working days in year 1989?

Here is the detail of the calculation:

Because 1989 is not a leap year, it has 365 days.

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

Now, let's remove 6 public holidays that do not fall during a weekend and we obtain 254 working days in 1989.

Here is the list of these 6 public holidays:

1. Día de la Constitución : Monday, 6 February, 1989
2. Natalicio de Benito Juárez : Monday, 20 March, 1989
3. Viernes Santo : Friday, 24 March, 1989
4. Día del Trabajo : Monday, 1 May, 1989
5. Día de la Revolución : Monday, 20 November, 1989
6. Navidad : Monday, 25 December, 1989

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

1. Año Nuevo : Sunday, 1 January, 1989
2. Día de la Independencia : Saturday, 16 September, 1989