Define a period

...

How many working days in year 1957?

Here is the detail of the calculation:

Because 1957 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 11 public holidays that do not fall during a weekend and we obtain 250 working days in 1957.

Here is the list of these 11 public holidays:

1. Jour de l'An : Tuesday, 1 January, 1957
2. Lundi de Pâques : Monday, 22 April, 1957
3. Fête du Travail : Wednesday, 1 May, 1957
4. Jeudi de l'Ascension : Thursday, 30 May, 1957
5. Lundi de la Pentecôte : Monday, 10 June, 1957
6. Jour de la fête Dieu : Thursday, 20 June, 1957
7. Fête de l'Assomption : Thursday, 15 August, 1957
8. Fête de la Toussaint : Friday, 1 November, 1957
9. Fête Nationale : Tuesday, 19 November, 1957
10. Fête de l'Immaculée Conception : Monday, 9 December, 1957
11. Jour de Noël : Wednesday, 25 December, 1957

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

1. Jour de la Sainte Dévote : Sunday, 27 January, 1957
2. Fête de l'Immaculée Conception : Sunday, 8 December, 1957