In most legal systems, one becomes designated as an adult on a particular birthday (usually between 12 and 21), and reaching age-specific milestones confers particular rights and responsibilities. At certain ages, one may become eligible to leave full-time education, become subject to military conscription or to enlist in the military, to consent to sexual intercourse, to marry, to marry without parental consent, to vote, to run for elected office, to legally purchase alcohol and tobacco products, to purchase lottery tickets, or to obtain a driver’s licence.
The age of majority is the age when minors cease to legally be considered children and assume control over their persons, actions, and decisions, thereby terminating the legal control and legal responsibilities of their parents or guardians over and for them. Most countries set the age of majority between 18 and 21.
In many parts of the world an individual’s birthday is celebrated by a party where a specially made cake, usually decorated with lettering and the person’s age, is presented. The cake is traditionally studded with the same number of lit candles as the age of the individual, or a number candle representing their age. The celebrated individual will usually make a silent wish and attempt to blow out the candles in one breath; if successful, a tradition holds that the wish will be granted.
In many cultures, the wish must be kept secret or it won’t “come true”.
Presents are bestowed on the individual by the guests appropriate to her/his age. Other birthday activities may include entertainment (sometimes by a hired professional, i.e. a clown, magician, or musician), and a special toast or speech by the birthday celebrant. The last stanza of Patty Hill’s and Mildred Hill’s famous song,
According to a public database of births, birthdays in the United States are quite evenly distributed for the most part, but there tend to be more births in September and October. This may be because there is a holiday season nine months before (the human gestation period is about nine months), or because the longest nights of the year also occur in the Northern Hemisphere nine months before. However, it appears the holidays have more of an effect on birth rates than the winter: New Zealand, a Southern Hemisphere country, has the same September and October peak with no corresponding peak in March and April.
The least common birthdays tend to fall around public holidays, such as Christmas, New Years Day and fixed-date holidays such as July 4 in the US. This is probably due to hospitals and birthing centres not offering labor inductions and elective Caesarean sections on public holidays.
Based on Harvard University research of birth records in the United States between 1973 and 1999, September 16 is the most common birthday in the United States and December 25 the least common birthday (other than February 29, because of leap years). In 2011, October 5 and 6 were reported as the most frequently occurring birthdays.