Define a period

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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 11 public holidays that do not fall during a weekend and we obtain 250 working days in 1981.

Here is the list of these 11 public holidays:

1. Restoration Day of the Independent Czech State : Thursday, 1 January, 1981
2. Good Friday : Friday, 17 April, 1981
3. Easter Monday : Monday, 20 April, 1981
4. Labour Day : Friday, 1 May, 1981
5. Liberation Day : Friday, 8 May, 1981
6. Jan Hus Day : Monday, 6 July, 1981
7. St Wenceslas Day : Monday, 28 September, 1981
8. Independence Day : Wednesday, 28 October, 1981
9. Freedom and Democracy Day : Tuesday, 17 November, 1981
10. Christmas Eve : Thursday, 24 December, 1981
11. Christmas Day : Friday, 25 December, 1981

And here are the 2 public holidays falling on a weekend:

1. St Cyril and Methodius' Day : Sunday, 5 July, 1981
2. St. Stephen's Day : Saturday, 26 December, 1981