Define a period

...

How many working days in year 1988?

Here is the detail of the calculation:

Because 1988 is a leap year, it has 366 days.

Let's remove 53 saturdays and 52 sundays. It remains 261 days.

Now, let's remove 6 public holidays that do not fall during a weekend and we obtain 255 working days in 1988.

Here is the list of these 6 public holidays:

1. Uusaasta : Friday, 1 January, 1988
2. Iseseisvuspäev : Wednesday, 24 February, 1988
3. Suur Reede : Friday, 1 April, 1988
4. Võidupüha : Thursday, 23 June, 1988
5. Jaanipäev : Friday, 24 June, 1988
6. Teine jõulupüha : Monday, 26 December, 1988

And here are the 6 public holidays falling on a weekend:

1. Ülestõusmispühad : Sunday, 3 April, 1988
2. Kevadpüha : Sunday, 1 May, 1988
3. Nelipühad : Sunday, 22 May, 1988
4. Taasiseseisvumispäev : Saturday, 20 August, 1988
5. Jõululaupäev : Saturday, 24 December, 1988
6. Esimene jõulupüha : Sunday, 25 December, 1988