Define a period

...

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 10 public holidays that do not fall during a weekend and we obtain 251 working days in 1990.

Here is the list of these 10 public holidays:

1. New Year's Day : Monday, 1 January, 1990
2. Maundy Thursday : Thursday, 12 April, 1990
3. Good Friday : Friday, 13 April, 1990
4. Easter Monday : Monday, 16 April, 1990
5. Labour Day : Tuesday, 1 May, 1990
6. Constitution Day : Thursday, 17 May, 1990
7. Ascension Day : Thursday, 24 May, 1990
8. Whit Monday : Monday, 4 June, 1990
9. Christmas Day : Tuesday, 25 December, 1990
10. St Stephen's Day : Wednesday, 26 December, 1990

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

1. Easter Sunday : Sunday, 15 April, 1990
2. Pentecost : Sunday, 3 June, 1990