Define a period

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How many working days in year 2021?

Here is the detail of the calculation:

Because 2021 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 2021.

Here is the list of these 12 public holidays:

1. New Year's Day : Friday, January 1, 2021
2. Martin Luther King Day : Monday, January 18, 2021
3. Washington's Birthday : Monday, February 15, 2021
4. Memorial Day : Monday, May 31, 2021
5. Juneteenth (observance) : Friday, June 18, 2021
6. Independence Day (observance) : Monday, July 5, 2021
7. Labor Day : Monday, September 6, 2021
8. Columbus Day : Monday, October 11, 2021
9. Veterans Day : Thursday, November 11, 2021
10. Thanksgiving : Thursday, November 25, 2021
11. Christmas (observance) : Friday, December 24, 2021
12. New Year's Day (observance) : Friday, December 31, 2021

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

1. Juneteenth National Independence Day : Saturday, June 19, 2021
2. Independence Day : Sunday, July 4, 2021
3. Christmas : Saturday, December 25, 2021