Armanx64: It takes the likeness of the Babylonian calendar - to 13 months, where 12 months - 30 days, and the last month - holidays. The new year begins on December 22nd, when the winter solstice. Five days of the thirteenth month + five days of the first - this is your New Year holidays.
On the summer solstice also five days of holidays - Half of the year.

Complaints about "business suffers because of the holidays" - your business. Leave the 60-hour working day to Prokhorov, we completely abolished slavery in the 17th year.