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How many working days in year 1980?

Here is the detail of the calculation:

Because 1980 is a leap year, it has 366 days.

Let's remove 52 saturdays and 52 sundays. It remains 262 days.

Now, let's remove 11 public holidays that do not fall during a weekend and we obtain 251 working days in 1980.

Here is the list of these 11 public holidays:

1. New Year's Day : вторник, 1 январь, 1980
2. Second Day of the New Year : среда, 2 январь, 1980
3. Union of the Romanian Principalities : четверг, 24 январь, 1980
4. Orthodox Easter Friday : пятница, 4 апрель, 1980
5. Orthodox Easter Monday : понедельник, 7 апрель, 1980
6. Labour Day : четверг, 1 май, 1980
7. Pentecost Monday : понедельник, 26 май, 1980
8. Assumption : пятница, 15 август, 1980
9. National Day : понедельник, 1 декабрь, 1980
10. Christmas Day : четверг, 25 декабрь, 1980
11. Boxing day : пятница, 26 декабрь, 1980

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

1. Orthodox Easter Sunday : воскресенье, 6 апрель, 1980
2. Pentecost Sunday : воскресенье, 25 май, 1980
3. Children's Day : воскресенье, 1 июнь, 1980
4. St. Andrew's Day : воскресенье, 30 ноябрь, 1980