Define a period

...

How many working days in year 1960?

Here is the detail of the calculation:

Because 1960 is a leap year, it has 366 days.

Let's remove 53 saturdays and 52 sundays. It remains 261 days.

Now, let's remove 8 public holidays that do not fall during a weekend and we obtain 253 working days in 1960.

Here is the list of these 8 public holidays:

1. New Year's Day : Friday, 1 January, 1960
2. Easter Monday : Monday, 18 April, 1960
3. Ascension Day : Thursday, 26 May, 1960
4. Pentecost Monday : Monday, 6 June, 1960
5. National Day : Thursday, 21 July, 1960
6. Assumption of Mary : Monday, 15 August, 1960
7. All Saints' Day : Tuesday, 1 November, 1960
8. Armistice Day : Friday, 11 November, 1960

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

1. Labor Day : Sunday, 1 May, 1960
2. Christmas Day : Sunday, 25 December, 1960