Define a period

...

How many working days in year 2017?

Here is the detail of the calculation:

Because 2017 is not a leap year, it has 365 days.

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

Now, let's remove 9 public holidays that do not fall during a weekend and we obtain 251 working days in 2017.

Here is the list of these 9 public holidays:

1. Skjærtorsdag : Thursday, 13 April, 2017
2. Langfredag : Friday, 14 April, 2017
3. Andre påskedag : Monday, 17 April, 2017
4. Første mai : Monday, 1 May, 2017
5. Grunnlovsdagen : Wednesday, 17 May, 2017
6. Kristi Himmelfartsdag : Thursday, 25 May, 2017
7. Andre pinsedag : Monday, 5 June, 2017
8. Første Juledag : Monday, 25 December, 2017
9. Andre Juledag : Tuesday, 26 December, 2017

And here are the 3 public holidays falling on a weekend:

1. Første nyttårsdag : Sunday, 1 January, 2017
2. Første påskedag : Sunday, 16 April, 2017
3. Første pinsedag : Sunday, 4 June, 2017