The graph below shows how births vary by day of the week and even by holidays using data on births from the CDC during the months of November, December, and January from 1994 to 2001. The blue lines depict the actual number of births, while the red lines show the average number of births by day of the week. The important part to notice is where they don’t line up.
The graph’s creator explains:
An obvious pattern for births by day of the week is seen: Weekend births (around 8000 per day) are significantly lower than weekday births (about 11,000 to 12,000 per day). This is due to scheduled births (both induced normal births and non-emergency caesarian births) taking place during the week, not on weekends. This daily pattern is consistent for most weeks of each three month period in this chart.
It is obvious that births on 1 January are markedly lower than would be expected for the day of the week. Births on 25 December (Christmas Day) are also lower than expected for the day of the week, by an even greater amount than the New Year’s Day variation. In fact, the day of the year with lowest number of births is Christmas Day. Thanksgiving also shows a pronounced decrease in births compared to typical Thursdays, and perhaps more of an effect than New Year’s. The day of the year with the greatest number of births is either the Tuesday before Thanksgiving (as in 2000), the Tuesday before Christmas (1999), or the Tuesday before New Year’s (1998).
The author’s interpretation:
It is evident that more births are induced just before these three holidays, so the patients and doctors are not tied up during the holidays.
Happy holidays! (Tongue firmly in cheek…)