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How many working days in year 1928?

Here is the detail of the calculation:

Because 1928 is a leap year, it has 366 days.

Let's remove 52 saturdays and 52 sundays. It remains 262 days.

Now, let's remove 5 public holidays that do not fall during a weekend and we obtain 257 working days in 1928.

Here is the list of these 5 public holidays:

1. Pesach : четверг, 5 апрель, 1928
2. Shvi'i shel Pesach : среда, 11 апрель, 1928
3. Yom Ha-Atzmaut : среда, 25 апрель, 1928
4. Rosh Hashanah : воскресенье, 16 сентябрь, 1928
5. Yom Kippur : понедельник, 24 сентябрь, 1928

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

1. Shavuot : пятница, 25 май, 1928
2. Rosh Hashanah : суббота, 15 сентябрь, 1928
3. Sukkot : суббота, 29 сентябрь, 1928
4. Shemini Atzeret / Simchat Torah : суббота, 6 октябрь, 1928