Define a period

...

How many working days in year 1979?

Here is the detail of the calculation:

Because 1979 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 9 public holidays that do not fall during a weekend and we obtain 252 working days in 1979.

Here is the list of these 9 public holidays:

1. New Year's Day : Monday, 1 January, 1979
2. Clean Monday : Monday, 5 March, 1979
3. Good Friday : Friday, 20 April, 1979
4. Easter Monday : Monday, 23 April, 1979
5. Labour Day : Tuesday, 1 May, 1979
6. Pentecost Monday : Monday, 11 June, 1979
7. Assumption : Wednesday, 15 August, 1979
8. Christmas : Tuesday, 25 December, 1979
9. Glorifying Mother of God : Wednesday, 26 December, 1979

And here are the 5 public holidays falling on a weekend:

1. Epiphany : Saturday, 6 January, 1979
2. Independence Day : Sunday, 25 March, 1979
3. Orthodox Easter : Sunday, 22 April, 1979
4. Pentecost : Sunday, 10 June, 1979
5. Ochi Day : Sunday, 28 October, 1979