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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 : вторник, 10 апрель, 1990
2. Shvi'i shel Pesach : понедельник, 16 апрель, 1990
3. Yom Ha-Atzmaut : понедельник, 30 апрель, 1990
4. Shavuot : среда, 30 май, 1990
5. Rosh Hashanah : четверг, 20 сентябрь, 1990
6. Sukkot : четверг, 4 октябрь, 1990
7. Shemini Atzeret / Simchat Torah : четверг, 11 октябрь, 1990

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

1. Rosh Hashanah : пятница, 21 сентябрь, 1990
2. Yom Kippur : суббота, 29 сентябрь, 1990