Birthday

Legal conventions

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 (or consume) 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.

Cultural conventions

Many cultures have one or more coming of age birthdays:

The birthdays of historically significant people, such as national heroes or founders, are often commemorated by an official holiday marking the anniversary of their birth.

A person's golden or grand birthday, also referred to as their "lucky birthday", "champagne birthday", or "star birthday", occurs when they turn the age of their birth day (e.g., when someone born on the 25th of the month turns 25 or when someone born on the ninth turns nine).

An individual's Beddian birthday, named in tribute to firefighter Bobby Beddia, occurs during the year that his or her age matches the last two digits of the year he or she was born.

In many cultures and jurisdictions, if a person's real birthday is not known (for example, if he or she is an orphan), then their birthday may be considered to be January 1. That tradition is followed with horses, their age becoming one, on the first day of the year following their birth and being counted annually after that.

Traditions

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, "Good Morning to You" (unofficially titled "Happy Birthday to You") is typically sung by the guests at some point in the proceedings. In some countries a piñata takes the place of a cake.

Name days

In some historically Roman Catholic and Eastern Orthodox countries such as Italy, Spain, France, parts of Germany, Poland, Russia, Romania, Bulgaria, Serbia, Slovakia, Czech Republic, Hungary, Greece, Lithuania, Latvia, and throughout Latin America, it is common to have a 'name day'/'Saint's day'. It is celebrated in much the same way as a birthday, but it is held on the official day of a saint with the same Christian name as the birthday person; the difference being that one may look up a person's name day in a calendar, or easily remember common name days (for example, John or Mary); however in pious traditions, the two were often made to concur by giving a newborn the name of a saint celebrated on its birthday, or possibly the name of a feast, for example, Noel or Pascal (French for Christmas and "of Easter"); as another example, Togliatti was given Palmiro as his first name because he was born on Palm Sunday.

Official birthdays

Some notables, particularly monarchs, have an official birthday on a fixed day of the year, which may not necessarily match the day of their birth, but on which celebrations are held. Examples are:

Frequency

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.

In New Zealand, the ten most common birthdays all fall within a thirteen-day period, between September 19 and October 1, corresponding to conception in December. The ten least common birthdays (other than February 29) are December 24–27, January 1–2, February 6, March 22, April 1 and April 25. This is based on all live births registered in New Zealand between 1980 and 2014.

According to a study by the Yale School of Public Health, positive and negative associations with culturally significant dates may influence birth rates. The study shows a 5.3% decrease in spontaneous births and a 16.9% decrease in Caesarean births on Halloween, compared to dates occurring within one week before and one week after the October holiday. In contrast, on Valentine's Day there is a 3.6% increase in spontaneous births and a 12.1% increase in Caesarean births.

Time zones and birthminutes

A person's birthday and birthminute is usually recorded according to the time zone of the place of birth. Therefore, for example, if one is born on October 20 at 13:13 UTC+11 in Sydney, Australia, this would be recorded as October 19 at 19:13 UTC−7 in Los Angeles. Such a person, if spending his or her birthday in Los Angeles, would celebrate on October 19. Due to the irregularity of the International Date Line, no person would celebrate his or her birthday on the same day everywhere in the world, and a person born between 10:00 and 11:59 UTC would have three possible birthdays at various positions on the globe. (since the earliest time zone used in the world is UTC-12 and the latest is UTC+14).

Leap day

In the Gregorian calendar (a common solar calendar), February in a leap year has 29 days instead of the usual 28, so the year lasts 366 days instead of the usual 365.

A person born on February 29 may be called a "leapling" or a "leaper". In common years they usually celebrate their birthdays on February 28. In some situations, March 1 is used as the birthday in a non-leap year since it is the day following February 28.

Technically, a leapling will have fewer birthday anniversaries than their age in years. This phenomenon is exploited when a person claims to be only a quarter of their actual age, by counting their leap-year birthday anniversaries only. In Gilbert and Sullivan's 1879 comic opera The Pirates of Penzance, Frederic the pirate apprentice discovers that he is bound to serve the pirates until his 21st birthday rather than until his 21st year.

For legal purposes, legal birthdays depend on how local laws count time intervals.

Ancient Persia

According to Herodotus (5th century BC), of all the days in the year, the one which the Persians celebrate most is their birthday. It was customary to have the board furnished on that day with an ampler supply than common: the richer people eat wholly baked cow, horse, camel, or donkey, while the poorer classes use instead the smaller kinds of cattle.

Ancient Rome

The Romans enthusiastically celebrated birthdays with hedonistic parties and generous presents.

China

Chinese birthday traditions reflect the culture's deep-seated focus on longevity and wordplay. From the homophony between 酒 ("rice wine") and 久 (meaning "long" in the sense of time passing), osmanthus and other rice wines are traditional gifts for birthdays in China. Longevity noodles are another traditional food consumed on the day, although western-style birthday cakes are increasingly common among urban Chinese.

Judaism

In Judaism, the perspective on birthday celebrations is disputed by various rabbis, although today it is accepted practice by most of the faithful. In the Hebrew Bible, the one single mention of a celebration being held in commemoration of someone's day of birth is for the Egyptian Pharaoh which is recorded in Genesis 40:20. Rabbi Moshe Feinstein always acknowledged birthdays. The Lubavitcher Rebbe encouraged people to celebrate their birthdays, by gathering friends, making positive resolutions, and through various religious observances. According to Rabbi Yissocher Frand, the anniversary of a person's birth is a special day for that person's prayers to be accepted.

The bar mitzvah of 13-year-old Jewish boys, or bat mitzvah for 12-year-old Jewish girls, is perhaps the only Jewish celebration undertaken in what is often perceived to be in coalition with a birthday. Despite modern celebrations where the secular "birthday" element often overshadows the essence of it as a religious rite, the essence of a bar mitzvah or bat mitzvah celebration is entirely religious in origin (i.e. the attainment of religious maturity according to Jewish law), however, and not secular. With or without the birthday celebration, the child nevertheless becomes a bar mitzvah or bat mitzvah, and the celebration may be on that day or any date after it.

Christianity: Early centuries

Origen in his commentary "On Levites" writes that Christians should not only refrain from celebrating their birthdays, but should look on them with disgust.

Orthodox Christianity in addition to birthdays, also celebrate the name day of a person.

Christianity: Medieval

Ordinary folk celebrated their saint's day (the saint they were named after), but nobility celebrated the anniversary of their birth. The "Squire's Tale", one of Chaucer's Canterbury Tales, opens as King Cambuskan proclaims a feast to celebrate his birthday.

Religious: Modern

While almost all Christians accept the practice today, Jehovah's Witnesses and some Sacred Name groups refrain from celebrating birthdays due to the custom's pagan origins, its connections to magic and superstitions. While Christmas is the celebration of Christ's Birth, some religious groups see it as being portrayed in a negative light.

Islam

Some consider the celebration of a birthday to be a sin, as it is considered an "innovation" of the faith, or bi'dah while other clerics have issued statements saying that the celebration of a birthday is permissible.

Some Muslims migrating to the United States adopt the custom of celebrating birthdays, especially for children, but others resist.

There is also a great deal of controversy regarding celebrating Mawlid (the anniversary of the birth of Muhammad). While a section of Islam strongly favours it, others decry such celebrations, terming them as out of the scope of Islam.

Hinduism

Hindus celebrate the birth anniversary day every year when the day that corresponds to lunar month or solar month (Sun Signs Nirayana System – Sourava Mana Masa) of birth and has the same asterism (Star/Nakshatra) as that of the date of birth. That age is reckoned whenever Janma Nakshatra of the same month passes.

Hindus regard death to be more auspicious than birth since the person is liberated from the bondages of material society. Also, traditionally, rituals & prayers for the departed are observed on 5th and 11th day with many relatives gathering.

Buddhism (Mahayana)

Many monasteries celebrate the anniversary of Buddha's birth, usually in a highly formal, ritualized manner. They treat Buddha's statue as if it was Buddha himself, as if he were alive; bathing, and "feeding" him.

Sikhism

Sikhs celebrate the anniversary of the birth of Guru Nanak.

North Korea

In North Korea, people do not celebrate birthdays on July 8 and December 17 because these were the dates of the deaths of Kim Il-sung and Kim Jong-il, respectively. More than 100,000 North Koreans celebrate displaced birthdays on July 9 or December 18 to avoid these dates. A person born on July 8 before 1994 may change their birthday, with official recognition. Kim Il-sung's birthday, Day of the Sun, is the most important public holiday of the country, and Kim Jong-il's birthday is celebrated as Day of the Shining Star.