Define a period

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How many working days in year 1990?

Here is the detail of the calculation:

Because 1990 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 1990.

Here is the list of these 11 public holidays:

1. Restoration Day of the Independent Czech State : Monday, 1 January, 1990
2. Good Friday : Friday, 13 April, 1990
3. Easter Monday : Monday, 16 April, 1990
4. Labour Day : Tuesday, 1 May, 1990
5. Liberation Day : Tuesday, 8 May, 1990
6. St Cyril and Methodius' Day : Thursday, 5 July, 1990
7. Jan Hus Day : Friday, 6 July, 1990
8. St Wenceslas Day : Friday, 28 September, 1990
9. Christmas Eve : Monday, 24 December, 1990
10. Christmas Day : Tuesday, 25 December, 1990
11. St. Stephen's Day : Wednesday, 26 December, 1990

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

1. Independence Day : Sunday, 28 October, 1990
2. Freedom and Democracy Day : Saturday, 17 November, 1990