Define a period

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How many working days in year 2057?

Here is the detail of the calculation:

Because 2057 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 2057.

Here is the list of these 13 public holidays:

1. 신정 : Monday, 1 January, 2057
2. Seollal / Korean New Year Holiday : Monday, 5 February, 2057
3. 삼일절 : Thursday, 1 March, 2057
4. 어린이날 : Monday, 7 May, 2057
5. 석가탄신일 : Friday, 11 May, 2057
6. 현충일 : Wednesday, 6 June, 2057
7. 광복절 : Wednesday, 15 August, 2057
8. 추석 : Wednesday, 12 September, 2057
9. 추석 : Thursday, 13 September, 2057
10. 추석 : Friday, 14 September, 2057
11. 개천절 : Wednesday, 3 October, 2057
12. 한글날 : Tuesday, 9 October, 2057
13. 성탄절 : Tuesday, 25 December, 2057

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

1. Seollal / Korean New Year Holiday : Saturday, 3 February, 2057
2. Seollal / Korean New Year Holiday : Sunday, 4 February, 2057
3. 어린이날 : Saturday, 5 May, 2057