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 11 public holidays that do not fall during a weekend and we obtain 249 working days in 1989.

Here is the list of these 11 public holidays:

1. Second Day of the New Year : понедельник, 2 январь, 1989
2. Union of the Romanian Principalities : вторник, 24 январь, 1989
3. Orthodox Easter Friday : пятница, 28 апрель, 1989
4. Orthodox Easter Monday : понедельник, 1 май, 1989
5. Children's Day : четверг, 1 июнь, 1989
6. Pentecost Monday : понедельник, 19 июнь, 1989
7. Assumption : вторник, 15 август, 1989
8. St. Andrew's Day : четверг, 30 ноябрь, 1989
9. National Day : пятница, 1 декабрь, 1989
10. Christmas Day : понедельник, 25 декабрь, 1989
11. Boxing day : вторник, 26 декабрь, 1989

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

1. New Year's Day : воскресенье, 1 январь, 1989
2. Orthodox Easter Sunday : воскресенье, 30 апрель, 1989
3. Pentecost Sunday : воскресенье, 18 июнь, 1989