Define a period

...

How many working days in year 1999?

Here is the detail of the calculation:

Because 1999 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 6 public holidays that do not fall during a weekend and we obtain 255 working days in 1999.

Here is the list of these 6 public holidays:

1. Nieuwjaar : Friday, 1 January, 1999
2. Goede Vrijdag : Friday, 2 April, 1999
3. Tweede Paasdag : Monday, 5 April, 1999
4. Koninginnedag : Friday, 30 April, 1999
5. Hemelvaartsdag : Thursday, 13 May, 1999
6. Tweede Pinksterdag : Monday, 24 May, 1999

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

1. Eerste Paasdag : Sunday, 4 April, 1999
2. Eerste Pinksterdag : Sunday, 23 May, 1999
3. Eerste Kerstdag : Saturday, 25 December, 1999
4. Tweede Kerstdag : Sunday, 26 December, 1999