Define a period

...

How many working days in year 1971?

Here is the detail of the calculation:

Because 1971 is not a leap year, it has 365 days.

Let's remove 52 saturdays and 52 sundays. It remains 261 days.

Now, let's remove 10 public holidays that do not fall during a weekend and we obtain 251 working days in 1971.

Here is the list of these 10 public holidays:

1. Jour de l'An : Friday, 1 January, 1971
2. Jour de la Sainte Dévote : Wednesday, 27 January, 1971
3. Lundi de Pâques : Monday, 12 April, 1971
4. Jeudi de l'Ascension : Thursday, 20 May, 1971
5. Lundi de la Pentecôte : Monday, 31 May, 1971
6. Jour de la fête Dieu : Thursday, 10 June, 1971
7. Fête de l'Assomption : Monday, 16 August, 1971
8. Fête de la Toussaint : Monday, 1 November, 1971
9. Fête Nationale : Friday, 19 November, 1971
10. Fête de l'Immaculée Conception : Wednesday, 8 December, 1971

And here are the 3 public holidays falling on a weekend:

1. Fête du Travail : Saturday, 1 May, 1971
2. Fête de l'Assomption : Sunday, 15 August, 1971
3. Jour de Noël : Saturday, 25 December, 1971