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. Jour de l'An : Tuesday, 1 January, 1980
2. Lundi de Pâques : Monday, 7 April, 1980
3. Fête du Travail : Thursday, 1 May, 1980
4. Jeudi de l'Ascension : Thursday, 15 May, 1980
5. Lundi de la Pentecôte : Monday, 26 May, 1980
6. Jour de la fête Dieu : Thursday, 5 June, 1980
7. Fête de l'Assomption : Friday, 15 August, 1980
8. Fête Nationale : Wednesday, 19 November, 1980
9. Fête de l'Immaculée Conception : Monday, 8 December, 1980
10. Jour de Noël : Thursday, 25 December, 1980

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

1. Jour de la Sainte Dévote : Sunday, 27 January, 1980
2. Fête de la Toussaint : Saturday, 1 November, 1980