Define a period

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How many working days in year 1978?

Here is the detail of the calculation:

Because 1978 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 1978.

Here is the list of these 8 public holidays:

1. Purim : Thursday, 23 March, 1978
2. Yom Ha-Atzmaut : Thursday, 11 May, 1978
3. Shavuot : Sunday, 11 June, 1978
4. Rosh Hashanah : Monday, 2 October, 1978
5. Rosh Hashanah : Tuesday, 3 October, 1978
6. Yom Kippur : Wednesday, 11 October, 1978
7. Sukkot : Monday, 16 October, 1978
8. Shemini Atzeret / Simchat Torah : Monday, 23 October, 1978

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

1. Pesach : Saturday, 22 April, 1978
2. Shvi'i shel Pesach : Friday, 28 April, 1978