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 10 public holidays that do not fall during a weekend and we obtain 251 working days in 1997.

Here is the list of these 10 public holidays:

1. Restoration Day of the Independent Czech State : 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. Liberation Day : четверг, 8 май, 1997
6. Independence Day : вторник, 28 октябрь, 1997
7. Freedom and Democracy Day : понедельник, 17 ноябрь, 1997
8. Christmas Eve : среда, 24 декабрь, 1997
9. Christmas Day : четверг, 25 декабрь, 1997
10. St. Stephen's Day : пятница, 26 декабрь, 1997

And here are the 3 public holidays falling on a weekend:

1. St Cyril and Methodius' Day : суббота, 5 июль, 1997
2. Jan Hus Day : воскресенье, 6 июль, 1997
3. St Wenceslas Day : воскресенье, 28 сентябрь, 1997