Define a period

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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 11 public holidays that do not fall during a weekend and we obtain 251 working days in 1980.

Here is the list of these 11 public holidays:

1. New Year's Day : Tuesday, 1 January, 1980
2. Second Day of the New Year : Wednesday, 2 January, 1980
3. Union of the Romanian Principalities : Thursday, 24 January, 1980
4. Orthodox Easter Friday : Friday, 4 April, 1980
5. Orthodox Easter Monday : Monday, 7 April, 1980
6. Labour Day : Thursday, 1 May, 1980
7. Pentecost Monday : Monday, 26 May, 1980
8. Assumption : Friday, 15 August, 1980
9. National Day : Monday, 1 December, 1980
10. Christmas Day : Thursday, 25 December, 1980
11. Boxing day : Friday, 26 December, 1980

And here are the 4 public holidays falling on a weekend:

1. Orthodox Easter Sunday : Sunday, 6 April, 1980
2. Pentecost Sunday : Sunday, 25 May, 1980
3. Children's Day : Sunday, 1 June, 1980
4. St. Andrew's Day : Sunday, 30 November, 1980