Define a period

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How many working days in year 1999?

Here is the detail of the calculation:

Because 1999 is not a leap year, it has 365 days.

Let's remove 53 saturdays and 52 sundays. It remains 260 days.

Now, let's remove 5 public holidays that do not fall during a weekend and we obtain 255 working days in 1999.

Here is the list of these 5 public holidays:

1. פסח : Thursday, 1 April, 1999
2. שביעי של פסח : Wednesday, 7 April, 1999
3. יום העצמאות : Wednesday, 21 April, 1999
4. ראש השנה : Sunday, 12 September, 1999
5. יום כיפור : Monday, 20 September, 1999

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

1. שבועות : Friday, 21 May, 1999
2. ראש השנה : Saturday, 11 September, 1999
3. סוכות : Saturday, 25 September, 1999
4. שמחת תורה/שמיני עצרת : Saturday, 2 October, 1999