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How many working days in year 1900?

Here is the detail of the calculation:

Because 1900 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 1900.

Here is the list of these 8 public holidays:

1. Purim : четверг, 15 март, 1900
2. Yom Ha-Atzmaut : четверг, 3 май, 1900
3. Shavuot : воскресенье, 3 июнь, 1900
4. Rosh Hashanah : понедельник, 24 сентябрь, 1900
5. Rosh Hashanah : вторник, 25 сентябрь, 1900
6. Yom Kippur : среда, 3 октябрь, 1900
7. Sukkot : понедельник, 8 октябрь, 1900
8. Shemini Atzeret / Simchat Torah : понедельник, 15 октябрь, 1900

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

1. Pesach : суббота, 14 апрель, 1900
2. Shvi'i shel Pesach : пятница, 20 апрель, 1900