Определить период

...

How many working days in year 1997?

Here is the detail of the calculation:

Because 1997 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 1997.

Here is the list of these 9 public holidays:

1. New Year's Day : среда, 1 январь, 1997
2. Good Friday : пятница, 28 март, 1997
3. Easter Monday : понедельник, 31 март, 1997
4. Labour Day : четверг, 1 май, 1997
5. Pentecost Monday : понедельник, 19 май, 1997
6. State Foundation Day : среда, 20 август, 1997
7. National Day : четверг, 23 октябрь, 1997
8. Christmas Day : четверг, 25 декабрь, 1997
9. Second Day of Christmas : пятница, 26 декабрь, 1997

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

1. National Day : суббота, 15 март, 1997
2. Easter Sunday : воскресенье, 30 март, 1997
3. Pentecost Sunday : воскресенье, 18 май, 1997
4. All Saints' Day : суббота, 1 ноябрь, 1997