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 10 public holidays that do not fall during a weekend and we obtain 251 working days in 1987.

Here is the list of these 10 public holidays:

1. New Year's Day : Thursday, 1 January, 1987
2. Australia Day : Monday, 26 January, 1987
3. Canberra Day : Monday, 9 March, 1987
4. Good Friday : Friday, 17 April, 1987
5. Easter Monday : Monday, 20 April, 1987
6. Anzac Day observance : Monday, 27 April, 1987
7. King's Birthday : Monday, 8 June, 1987
8. Labour Day : Monday, 5 October, 1987
9. Christmas Day : Friday, 25 December, 1987
10. Boxing Day Observance : Monday, 28 December, 1987

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

1. Easter Saturday : Saturday, 18 April, 1987
2. Easter Sunday : Sunday, 19 April, 1987
3. Anzac Day : Saturday, 25 April, 1987
4. Boxing Day : Saturday, 26 December, 1987