Define a period

...

How many working days in year 1915?

Here is the detail of the calculation:

Because 1915 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 7 public holidays that do not fall during a weekend and we obtain 254 working days in 1915.

Here is the list of these 7 public holidays:

1. Uusaasta : Friday, 1 January, 1915
2. Iseseisvuspäev : Wednesday, 24 February, 1915
3. Suur Reede : Friday, 2 April, 1915
4. Võidupüha : Wednesday, 23 June, 1915
5. Jaanipäev : Thursday, 24 June, 1915
6. Taasiseseisvumispäev : Friday, 20 August, 1915
7. Jõululaupäev : Friday, 24 December, 1915

And here are the 5 public holidays falling on a weekend:

1. Ülestõusmispühad : Sunday, 4 April, 1915
2. Kevadpüha : Saturday, 1 May, 1915
3. Nelipühad : Sunday, 23 May, 1915
4. Esimene jõulupüha : Saturday, 25 December, 1915
5. Teine jõulupüha : Sunday, 26 December, 1915