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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 9 public holidays that do not fall during a weekend and we obtain 253 working days in 1980.

Here is the list of these 9 public holidays:

1. Neujahrstag : вторник, 1 январь, 1980
2. Karfreitag : пятница, 4 апрель, 1980
3. Ostermontag : понедельник, 7 апрель, 1980
4. Staatsfeiertag : четверг, 1 май, 1980
5. Pfingstmontag : понедельник, 26 май, 1980
6. Heiliger Abend : среда, 24 декабрь, 1980
7. Weihnachten : четверг, 25 декабрь, 1980
8. Stefanitag : пятница, 26 декабрь, 1980
9. Silvesters : среда, 31 декабрь, 1980

And here is the public holiday falling on a weekend:

1. Nationalfeiertag : воскресенье, 26 октябрь, 1980