Define a period

...

How many working days in year 1901?

Here is the detail of the calculation:

Because 1901 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 1901.

Here is the list of these 13 public holidays:

1. New Year's Day : Tuesday, 1 January, 1901
2. Seollal / Korean New Year Holiday : Monday, 18 February, 1901
3. Seollal / Korean New Year Holiday : Tuesday, 19 February, 1901
4. Seollal / Korean New Year Holiday : Wednesday, 20 February, 1901
5. Independence Movement Day : Friday, 1 March, 1901
6. Children's Day : Monday, 6 May, 1901
7. Memorial Day : Thursday, 6 June, 1901
8. Liberation Day : Thursday, 15 August, 1901
9. Chuseok / Midautumn Festival : Thursday, 26 September, 1901
10. Chuseok / Midautumn Festival : Friday, 27 September, 1901
11. National Foundation Day : Thursday, 3 October, 1901
12. Hangeul Day : Wednesday, 9 October, 1901
13. Christmas Day : Wednesday, 25 December, 1901

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

1. Children's Day : Sunday, 5 May, 1901
2. Buddha's Birthday : Saturday, 25 May, 1901
3. Chuseok / Midautumn Festival : Saturday, 28 September, 1901