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 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 : Thursday, 1 January, 1981
2. Epiphany : Tuesday, 6 January, 1981
3. Clean Monday : Monday, 9 March, 1981
4. Independence Day : Wednesday, 25 March, 1981
5. Good Friday : Friday, 24 April, 1981
6. Easter Monday : Monday, 27 April, 1981
7. Labour Day : Friday, 1 May, 1981
8. Pentecost Monday : Monday, 15 June, 1981
9. Ochi Day : Wednesday, 28 October, 1981
10. Christmas : Friday, 25 December, 1981

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

1. Orthodox Easter : Sunday, 26 April, 1981
2. Pentecost : Sunday, 14 June, 1981
3. Assumption : Saturday, 15 August, 1981
4. Glorifying Mother of God : Saturday, 26 December, 1981