Определить период

...

How many working days in year 1919?

Here is the detail of the calculation:

Because 1919 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 9 public holidays that do not fall during a weekend and we obtain 252 working days in 1919.

Here is the list of these 9 public holidays:

1. New Year's Day : среда, 1 январь, 1919
2. Good Friday : пятница, 18 апрель, 1919
3. Easter Monday : понедельник, 21 апрель, 1919
4. Labour Day : четверг, 1 май, 1919
5. Pentecost Monday : понедельник, 9 июнь, 1919
6. State Foundation Day : среда, 20 август, 1919
7. National Day : четверг, 23 октябрь, 1919
8. Christmas Day : четверг, 25 декабрь, 1919
9. Second Day of Christmas : пятница, 26 декабрь, 1919

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

1. National Day : суббота, 15 март, 1919
2. Easter Sunday : воскресенье, 20 апрель, 1919
3. Pentecost Sunday : воскресенье, 8 июнь, 1919
4. All Saints' Day : суббота, 1 ноябрь, 1919