Define a period

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How many working days in year 1987?

Here is the detail of the calculation:

Because 1987 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 9 public holidays that do not fall during a weekend and we obtain 252 working days in 1987.

Here is the list of these 9 public holidays:

1. Nieuwjaarsdag : Thursday, 1 January, 1987
2. Paasmaandag : Monday, 20 April, 1987
3. Dag van de Arbeid : Friday, 1 May, 1987
4. Irisfeest : Friday, 8 May, 1987
5. Hemelvaartsdag : Thursday, 28 May, 1987
6. Pinkstermaandag : Monday, 8 June, 1987
7. Nationale Feestdag : Tuesday, 21 July, 1987
8. Wapenstilstand : Wednesday, 11 November, 1987
9. Kerstmis : Friday, 25 December, 1987

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

1. Onze-Lieve-Vrouw Hemelvaart : Saturday, 15 August, 1987
2. Allerheiligen : Sunday, 1 November, 1987