September appears to be the most common month for birthdays worldwide, with nine of the 10 most frequent birth dates falling in the month, according to World Atlas.
The report notes that birthday patterns vary across countries, influenced by cultural traditions, seasonal changes and other factors.
However, births tend to increase during the final weeks of summer and the beginning of autumn. Some European countries, meanwhile, record higher birth rates during spring.
Seasonal birth patterns also differ in the Southern Hemisphere, where seasons are opposite to those in the Northern Hemisphere.
According to World Atlas, September 9 is the most common birthday worldwide, followed by September 19 in second place and September 12 in third.
September 17 ranks fourth, while September 10 takes fifth place. July 7 is the only date outside September to feature in the top 10, ranking sixth.
The remaining dates are September 20 (seventh), September 15 (eighth), September 16 (ninth) and September 18 (10th).
The report acknowledges that birthday patterns differ across the world, making it difficult to establish a universally applicable ranking, but September clearly dominates its list.
