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How many working days in year 1981?

Here is the detail of the calculation:

Because 1981 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 1981.

Here is the list of these 10 public holidays:

1. New Year's Day : четверг, 1 январь, 1981
2. St. Patrick's Day : вторник, 17 март, 1981
3. Good Friday : пятница, 17 апрель, 1981
4. Easter Monday : понедельник, 20 апрель, 1981
5. Early May Bank Holiday : понедельник, 4 май, 1981
6. Spring Bank Holiday : понедельник, 25 май, 1981
7. Orangemen's Day : понедельник, 13 июль, 1981
8. Late Summer Bank Holiday : понедельник, 31 август, 1981
9. Christmas Day : пятница, 25 декабрь, 1981
10. Boxing Day (substitute day) : понедельник, 28 декабрь, 1981

And here is the public holiday falling on a weekend:

1. Orangemen's Day : воскресенье, 12 июль, 1981