Определить период

...

How many working days in year 1989?

Here is the detail of the calculation:

Because 1989 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 6 public holidays that do not fall during a weekend and we obtain 254 working days in 1989.

Here is the list of these 6 public holidays:

1. Independence Day : пятница, 24 февраль, 1989
2. Good Friday : пятница, 24 март, 1989
3. Spring Day : понедельник, 1 май, 1989
4. Victory Day : пятница, 23 июнь, 1989
5. Christmas Day : понедельник, 25 декабрь, 1989
6. Second Day of Christmas : вторник, 26 декабрь, 1989

And here are the 6 public holidays falling on a weekend:

1. New Year's Day : воскресенье, 1 январь, 1989
2. Easter : воскресенье, 26 март, 1989
3. Pentecost : воскресенье, 14 май, 1989
4. Midsummer Day : суббота, 24 июнь, 1989
5. Independence Restoration Day : воскресенье, 20 август, 1989
6. Christmas Eve : воскресенье, 24 декабрь, 1989