Define a period

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How many working days in year 1986?

Here is the detail of the calculation:

Because 1986 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 6 public holidays that do not fall during a weekend and we obtain 255 working days in 1986.

Here is the list of these 6 public holidays:

1. Purim : Tuesday, 25 March, 1986
2. Pesach : Thursday, 24 April, 1986
3. Shvi'i shel Pesach : Wednesday, 30 April, 1986
4. Yom Ha-Atzmaut : Wednesday, 14 May, 1986
5. Rosh Hashanah : Sunday, 5 October, 1986
6. Yom Kippur : Monday, 13 October, 1986

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

1. Shavuot : Friday, 13 June, 1986
2. Rosh Hashanah : Saturday, 4 October, 1986
3. Sukkot : Saturday, 18 October, 1986
4. Shemini Atzeret / Simchat Torah : Saturday, 25 October, 1986