Define a period

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How many working days in year 2104?

Here is the detail of the calculation:

Because 2104 is a leap year, it has 366 days.

Let's remove 52 saturdays and 52 sundays. It remains 262 days.

Now, let's remove 246 public holidays that do not fall during a weekend and we obtain 246 working days in 2104.

Here is the list of these 246 public holidays:

1. New Year's Day : Tuesday, 1 January, 2104
2. January 2 : Wednesday, 2 January, 2104
3. January 3 : Thursday, 3 January, 2104
4. Coming of Age Day : Monday, 14 January, 2104
5. Foundation Day : Monday, 11 February, 2104
6. Vernal Equinox Day : Thursday, 20 March, 2104
7. Shōwa Day : Tuesday, 29 April, 2104
8. Children's Day : Monday, 5 May, 2104
9. Marine Day : Monday, 21 July, 2104
10. Mountain Day : Monday, 11 August, 2104
11. Respect-for-Aged Day : Monday, 15 September, 2104
12. Autumnal Equinox Day : Tuesday, 23 September, 2104
13. Health and Sports Day : Monday, 13 October, 2104
14. Culture Day : Monday, 3 November, 2104
15. Labor Thanksgiving Day (observance) : Monday, 24 November, 2104
16. New Year's Eve : Wednesday, 31 December, 2104

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

1. Emperor's Birthday : Saturday, 23 February, 2104
2. Constitution Memorial Day : Saturday, 3 May, 2104
3. Greenery Day : Sunday, 4 May, 2104
4. Labor Thanksgiving Day : Sunday, 23 November, 2104