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How many working days in year 1991?

Here is the detail of the calculation:

Because 1991 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 1991.

Here is the list of these 10 public holidays:

1. Restoration Day of the Independent Czech State : вторник, 1 январь, 1991
2. Good Friday : пятница, 29 март, 1991
3. Easter Monday : понедельник, 1 апрель, 1991
4. Labour Day : среда, 1 май, 1991
5. Liberation Day : среда, 8 май, 1991
6. St Cyril and Methodius' Day : пятница, 5 июль, 1991
7. Independence Day : понедельник, 28 октябрь, 1991
8. Christmas Eve : вторник, 24 декабрь, 1991
9. Christmas Day : среда, 25 декабрь, 1991
10. St. Stephen's Day : четверг, 26 декабрь, 1991

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

1. Jan Hus Day : суббота, 6 июль, 1991
2. St Wenceslas Day : суббота, 28 сентябрь, 1991
3. Freedom and Democracy Day : воскресенье, 17 ноябрь, 1991