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How many working days in year 1920?

Here is the detail of the calculation:

Because 1920 is a leap year, it has 366 days.

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

Now, let's remove 7 public holidays that do not fall during a weekend and we obtain 255 working days in 1920.

Here is the list of these 7 public holidays:

1. New Year's Day : четверг, 1 январь, 1920
2. Good Friday : пятница, 2 апрель, 1920
3. Easter Monday : понедельник, 5 апрель, 1920
4. Queen's Day : пятница, 30 апрель, 1920
5. Liberation Day : среда, 5 май, 1920
6. Ascension Day : четверг, 13 май, 1920
7. Pentecost Monday : понедельник, 24 май, 1920

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

1. Easter Sunday : воскресенье, 4 апрель, 1920
2. Pentecost Sunday : воскресенье, 23 май, 1920
3. Christmas Day : суббота, 25 декабрь, 1920
4. Boxing Day : воскресенье, 26 декабрь, 1920