Define a period

...

How many working days in year 1974?

Here is the detail of the calculation:

Because 1974 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 15 public holidays that do not fall during a weekend and we obtain 246 working days in 1974.

Here is the list of these 15 public holidays:

1. 신정 : Tuesday, 1 January, 1974
2. Seollal / Korean New Year Holiday : Tuesday, 22 January, 1974
3. Seollal / Korean New Year Holiday : Wednesday, 23 January, 1974
4. Seollal / Korean New Year Holiday : Thursday, 24 January, 1974
5. 삼일절 : Friday, 1 March, 1974
6. 석가탄신일 : Monday, 29 April, 1974
7. 어린이날 : Monday, 6 May, 1974
8. 석가탄신일 : Wednesday, 29 May, 1974
9. 현충일 : Thursday, 6 June, 1974
10. 광복절 : Thursday, 15 August, 1974
11. 추석 : Monday, 30 September, 1974
12. 추석 : Tuesday, 1 October, 1974
13. 개천절 : Thursday, 3 October, 1974
14. 한글날 : Wednesday, 9 October, 1974
15. 성탄절 : Wednesday, 25 December, 1974

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

1. 어린이날 : Sunday, 5 May, 1974
2. 추석 : Sunday, 29 September, 1974