Define a period

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How many working days in year 1977?

Here is the detail of the calculation:

Because 1977 is not a leap year, it has 365 days.

Let's remove 53 saturdays and 52 sundays. It remains 260 days.

Now, let's remove 6 public holidays that do not fall during a weekend and we obtain 254 working days in 1977.

Here is the list of these 6 public holidays:

1. Loppiainen : Thursday, 6 January, 1977
2. Pitkäperjantai : Friday, 8 April, 1977
3. 2. pääsiäispäivä : Monday, 11 April, 1977
4. Helatorstai : Thursday, 19 May, 1977
5. Itsenäisyyspäivä : Tuesday, 6 December, 1977
6. Tapaninpäivä : Monday, 26 December, 1977

And here are the 7 public holidays falling on a weekend:

1. Uudenvuodenpäivä : Saturday, 1 January, 1977
2. Pääsiäispäivä : Sunday, 10 April, 1977
3. Vappu : Sunday, 1 May, 1977
4. Helluntaipäivä : Sunday, 29 May, 1977
5. Juhannuspäivä : Saturday, 25 June, 1977
6. Pyhäinpäivä : Saturday, 5 November, 1977
7. Joulupäivä : Sunday, 25 December, 1977