Define a period

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How many working days in year 1951?

Here is the detail of the calculation:

Because 1951 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 12 public holidays that do not fall during a weekend and we obtain 249 working days in 1951.

Here is the list of these 12 public holidays:

1. New Year's Day : Monday, 1 January, 1951
2. Seollal / Korean New Year Holiday : Monday, 5 February, 1951
3. Seollal / Korean New Year Holiday : Tuesday, 6 February, 1951
4. Seollal / Korean New Year Holiday : Wednesday, 7 February, 1951
5. Independence Movement Day : Thursday, 1 March, 1951
6. Children's Day : Monday, 7 May, 1951
7. Memorial Day : Wednesday, 6 June, 1951
8. Liberation Day : Wednesday, 15 August, 1951
9. Chuseok / Midautumn Festival : Friday, 14 September, 1951
10. National Foundation Day : Wednesday, 3 October, 1951
11. Hangeul Day : Tuesday, 9 October, 1951
12. Christmas Day : Tuesday, 25 December, 1951

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

1. Children's Day : Saturday, 5 May, 1951
2. Buddha's Birthday : Sunday, 13 May, 1951
3. Chuseok / Midautumn Festival : Saturday, 15 September, 1951
4. Chuseok / Midautumn Festival : Sunday, 16 September, 1951