Define a period

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How many working days in year 1985?

Here is the detail of the calculation:

Because 1985 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 13 public holidays that do not fall during a weekend and we obtain 248 working days in 1985.

Here is the list of these 13 public holidays:

1. 신정 : Tuesday, 1 January, 1985
2. Seollal / Korean New Year Holiday : Tuesday, 19 February, 1985
3. Seollal / Korean New Year Holiday : Wednesday, 20 February, 1985
4. Seollal / Korean New Year Holiday : Thursday, 21 February, 1985
5. 삼일절 : Friday, 1 March, 1985
6. 어린이날 : Monday, 6 May, 1985
7. 석가탄신일 : Monday, 27 May, 1985
8. 현충일 : Thursday, 6 June, 1985
9. 광복절 : Thursday, 15 August, 1985
10. 추석 : Monday, 30 September, 1985
11. 개천절 : Thursday, 3 October, 1985
12. 한글날 : Wednesday, 9 October, 1985
13. 성탄절 : Wednesday, 25 December, 1985

And here are the 3 public holidays falling on a weekend:

1. 어린이날 : Sunday, 5 May, 1985
2. 추석 : Saturday, 28 September, 1985
3. 추석 : Sunday, 29 September, 1985