Define a period

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How many working days in year 1972?

Here is the detail of the calculation:

Because 1972 is a leap year, it has 366 days.

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

Now, let's remove 5 public holidays that do not fall during a weekend and we obtain 256 working days in 1972.

Here is the list of these 5 public holidays:

1. Pesach : Thursday, 30 March, 1972
2. Shvi'i shel Pesach : Wednesday, 5 April, 1972
3. Yom Ha-Atzmaut : Wednesday, 19 April, 1972
4. Rosh Hashanah : Sunday, 10 September, 1972
5. Yom Kippur : Monday, 18 September, 1972

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

1. Shavuot : Friday, 19 May, 1972
2. Rosh Hashanah : Saturday, 9 September, 1972
3. Sukkot : Saturday, 23 September, 1972
4. Shemini Atzeret / Simchat Torah : Saturday, 30 September, 1972