Определить период

...

How many working days in year 1911?

Here is the detail of the calculation:

Because 1911 is not a leap year, it has 365 days.

Let's remove 52 saturdays and 53 sundays. It remains 260 days.

Now, let's remove 9 public holidays that do not fall during a weekend and we obtain 251 working days in 1911.

Here is the list of these 9 public holidays:

1. National Day : среда, 15 март, 1911
2. Good Friday : пятница, 14 апрель, 1911
3. Easter Monday : понедельник, 17 апрель, 1911
4. Labour Day : понедельник, 1 май, 1911
5. Pentecost Monday : понедельник, 5 июнь, 1911
6. National Day : понедельник, 23 октябрь, 1911
7. All Saints' Day : среда, 1 ноябрь, 1911
8. Christmas Day : понедельник, 25 декабрь, 1911
9. Second Day of Christmas : вторник, 26 декабрь, 1911

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

1. New Year's Day : воскресенье, 1 январь, 1911
2. Easter Sunday : воскресенье, 16 апрель, 1911
3. Pentecost Sunday : воскресенье, 4 июнь, 1911
4. State Foundation Day : воскресенье, 20 август, 1911