Define a period

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How many working days in year 1990?

Here is the detail of the calculation:

Because 1990 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 1990.

Here is the list of these 9 public holidays:

1. Nieuwjaarsdag : Monday, 1 January, 1990
2. Paasmaandag : Monday, 16 April, 1990
3. Dag van de Arbeid : Tuesday, 1 May, 1990
4. Hemelvaartsdag : Thursday, 24 May, 1990
5. Pinkstermaandag : Monday, 4 June, 1990
6. Onze-Lieve-Vrouw Hemelvaart : Wednesday, 15 August, 1990
7. Allerheiligen : Thursday, 1 November, 1990
8. Koningsdag : Thursday, 15 November, 1990
9. Kerstmis : Tuesday, 25 December, 1990

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

1. Nationale Feestdag : Saturday, 21 July, 1990
2. Wapenstilstand : Sunday, 11 November, 1990