Define a period

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How many working days in year 1982?

Here is the detail of the calculation:

Because 1982 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 14 public holidays that do not fall during a weekend and we obtain 247 working days in 1982.

Here is the list of these 14 public holidays:

1. New Year's Day : Friday, 1 January, 1982
2. Coming of Age Day : Monday, 11 January, 1982
3. Foundation Day : Thursday, 11 February, 1982
4. Shōwa Day : Thursday, 29 April, 1982
5. Constitution Memorial Day : Monday, 3 May, 1982
6. Greenery Day : Tuesday, 4 May, 1982
7. Children's Day : Wednesday, 5 May, 1982
8. Marine Day : Monday, 19 July, 1982
9. Respect-for-Aged Day : Monday, 20 September, 1982
10. Autumnal Equinox Day : Thursday, 23 September, 1982
11. Health and Sports Day : Monday, 11 October, 1982
12. Culture Day : Wednesday, 3 November, 1982
13. Labor Thanksgiving Day : Tuesday, 23 November, 1982
14. Emperor's Birthday : Thursday, 23 December, 1982

And here is the public holiday falling on a weekend:

1. Vernal Equinox Day : Saturday, 20 March, 1982