Define a period

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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 7 public holidays that do not fall during a weekend and we obtain 254 working days in 1990.

Here is the list of these 7 public holidays:

1. Pesach : Tuesday, 10 April, 1990
2. Shvi'i shel Pesach : Monday, 16 April, 1990
3. Yom Ha-Atzmaut : Monday, 30 April, 1990
4. Shavuot : Wednesday, 30 May, 1990
5. Rosh Hashanah : Thursday, 20 September, 1990
6. Sukkot : Thursday, 4 October, 1990
7. Shemini Atzeret / Simchat Torah : Thursday, 11 October, 1990

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

1. Rosh Hashanah : Friday, 21 September, 1990
2. Yom Kippur : Saturday, 29 September, 1990