Определить период

...

How many working days in year 1977?

Here is the detail of the calculation:

Because 1977 is not a leap year, it has 365 days.

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

Now, let's remove 8 public holidays that do not fall during a weekend and we obtain 252 working days in 1977.

Here is the list of these 8 public holidays:

1. Good Friday : пятница, 8 апрель, 1977
2. Easter Monday : понедельник, 11 апрель, 1977
3. St Cyril and Methodius' Day : вторник, 5 июль, 1977
4. Jan Hus Day : среда, 6 июль, 1977
5. St Wenceslas Day : среда, 28 сентябрь, 1977
6. Independence Day : пятница, 28 октябрь, 1977
7. Freedom and Democracy Day : четверг, 17 ноябрь, 1977
8. St. Stephen's Day : понедельник, 26 декабрь, 1977

And here are the 5 public holidays falling on a weekend:

1. Restoration Day of the Independent Czech State : суббота, 1 январь, 1977
2. Labour Day : воскресенье, 1 май, 1977
3. Liberation Day : воскресенье, 8 май, 1977
4. Christmas Eve : суббота, 24 декабрь, 1977
5. Christmas Day : воскресенье, 25 декабрь, 1977