Define a period

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How many working days in year 1989?

Here is the detail of the calculation:

Because 1989 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 1989.

Here is the list of these 6 public holidays:

1. פורים : Tuesday, 21 March, 1989
2. פסח : Thursday, 20 April, 1989
3. שביעי של פסח : Wednesday, 26 April, 1989
4. יום העצמאות : Wednesday, 10 May, 1989
5. ראש השנה : Sunday, 1 October, 1989
6. יום כיפור : Monday, 9 October, 1989

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

1. שבועות : Friday, 9 June, 1989
2. ראש השנה : Saturday, 30 September, 1989
3. סוכות : Saturday, 14 October, 1989
4. שמחת תורה/שמיני עצרת : Saturday, 21 October, 1989