Define a period

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How many working days in year 1977?

Here is the detail of the calculation:

Because 1977 is not a leap year, it has 365 days.

Let's remove 53 saturdays and 52 sundays. It remains 260 days.

Now, let's remove 7 public holidays that do not fall during a weekend and we obtain 253 working days in 1977.

Here is the list of these 7 public holidays:

1. Paasmaandag : Monday, 11 April, 1977
2. Hemelvaartsdag : Thursday, 19 May, 1977
3. Pinkstermaandag : Monday, 30 May, 1977
4. Nationale Feestdag : Thursday, 21 July, 1977
5. Onze-Lieve-Vrouw Hemelvaart : Monday, 15 August, 1977
6. Allerheiligen : Tuesday, 1 November, 1977
7. Wapenstilstand : Friday, 11 November, 1977

And here are the 4 public holidays falling on a weekend:

1. Nieuwjaarsdag : Saturday, 1 January, 1977
2. Dag van de Arbeid : Sunday, 1 May, 1977
3. Irisfeest : Sunday, 8 May, 1977
4. Kerstmis : Sunday, 25 December, 1977