1 January — a surprisingly common birthday among immigrants, although it is relatively unpopular birthday for U.S. citizens. This writes NPR.
January 1 — New year. It is also the birthday of thousands of immigrants. Why? Because they fled from war or some other disaster in that part of the world where birthdays are not as important as here in the US. And when it came time to fill out the paperwork and do not have access to birth records — many just chose 1 Jan.
Immigration data for 2009 show that 11 000 of the nearly 80,000 refugees in the United States in the year indicated January 1 as the date of his birth. It is 14%, an incredibly large number.
For U.S. citizens who were born here the New year is actually one of the least popular birthday. The company FiveThirtyEight reviewed the data on birth over the period from 1994 to 2014, and 1 January took place 365 of the 366 possible, just ahead of Christmas. They pointed to the many variables that explain the popularity and unpopularity of particular dates, for example, the imposition of birth parents to avoid the holiday in the hospital, a leap day, or even Friday the 13th.
And the most popular days were in September, just about 9 months after the holidays.