The research of timing conceptions to holidays is relatively new in the united states. Since the 1930’s conceptions fluctuated seasonally greatly due to humidity, amounts of sunlight etc this still rings true for less developed countries. In developed countries many people are shielded from sunlight, heat, and humidity by working indoors, air condition and heating systems.

However according to biorhythm researchers and creators of sex products between Christmas and New Years there is an increase in sexual activity. This could be due to news year resolutions of starting a family or the extra consumption of alcohol and partying. Having Christmas sex isn’t just an American rite, having heavy Christmas and New Years sex has always been a characteristic of Christian cultures in which it has been studied says Gabriele Doblhammer.

British Researchers have gone as far as to say the Christmas and New Years period can be linked to Festivals of Fertility. Such Festivities are associated with more opportunities to socialize and
an hedonistic approach to life.

Trojan condom project manager David Johnson says there is a large peak in sales of their condoms during the Christmas season. Ironically the increase in sexual intercourse also shows itself in the U.S as a large number of births in September.