Define a period

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How many working days in year 1987?

Here is the detail of the calculation:

Because 1987 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 8 public holidays that do not fall during a weekend and we obtain 253 working days in 1987.

Here is the list of these 8 public holidays:

1. New Year's Day : Thursday, 1 January, 1987
2. Easter Monday : Monday, 20 April, 1987
3. Labor Day : Friday, 1 May, 1987
4. Ascension Day : Thursday, 28 May, 1987
5. Pentecost Monday : Monday, 8 June, 1987
6. National Day : Tuesday, 21 July, 1987
7. Armistice Day : Wednesday, 11 November, 1987
8. Christmas Day : Friday, 25 December, 1987

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

1. Assumption of Mary : Saturday, 15 August, 1987
2. All Saints' Day : Sunday, 1 November, 1987