My wife has three birthdays. Although the Gregorian calendar was adopted in Korea in 1896, people continued to use the traditional Korean lunar calendar for everyday purposes. So, her family marked her birthday as 196>년 6월 28일 (using the Gregorian year but the traditional month and day). But her grandfather or father didn’t register her birthday, or indeed the birthdays of any of her older sisters, until her first younger brother was born, and then he managed to get two of those dates wrong. Her oldest and third sisters, and her older younger brother, have the correct date, but her second sister has the wrong year and she has the wrong year and day. Her youngest brother, who was registered separately after he was born, has the the wrong month and day.
She said that this happened all the time in those days, and many people have official dates of birth one to three years away from their real one. It is possible to apply to the Registry of Births, Deaths and Marriages or a court to have one’s official date of birth changed, but with the cost and effort, very few people bother. So, her official date of birth is one year earlier, on another day in June (but her lunar calendar birthday never falls in June anyway).
Until she moved to Australia, she celebrated her birthday on 음력 (eum-nyeok, lunar calendar) 6월 28일. This, like any lunar calendar date, jumps around in the solar calendar. Modern calendars printed in Korea, and the calendar app on my Samsung phone, are based on the solar calendar, but have the lunar calendar dates printed in smaller type at the bottom of the square (perhaps every day, perhaps once a week). I can’t remember what we did for her birthday in the two years I lived in Korea the first time.
Before she moved to Australia, we talked about when she would celebrate her birthday here. One possibility was to keep the lunar calendar birthday, but she decided against that, partly for the benefit of my Australian family. Or, she could simply transfer that lunar calendar date to the solar calendar, so that 음력 6월 28일, becomes 28 June. But one of my nephews has his birthday on 27 June, and I wanted to avoid that. Or, we could look for a lunar to solar calendar conversion website, which I did (I don’t know what people did in the days before the internet), and found that she was born on 4 August, so we decided on that: it is the same day of the month as mine, and in a nice little gap between the birthdays of my other family members.
The serious consequence of this is that the governments of South Korea and Australia think that she’s a year older than she is. The government of South Korea thought she should start school a year sooner than she otherwise would, but school enrolment was not rigidly observed by the families (especially for fourth daughters) or enforced by the government in small country towns in the early 1970s (the family moved to Seoul soon after, and she started school there). She said that students in school classes were often one or two years older or younger. This would have played havoc with Korean society and language’s hierarchy of seniority and juniority: this person is older than me, that person is younger than me, but we are in the same school class.
In Australia, the government has a health initiative for x0 year olds, and her information package for it came last June. On the other hand, she will one day be eligible for the pension and other senior services a year earlier than she otherwise would.
So, my wife’s three birthdays are 음력 196> 6월 28일, __ June 196< and 4 August 196>. When I asked her about all this, she expressed great surprise that I was remotely interested.
(PS When I was teaching at a high school in South Korea, I saw at the back of one classroom a ‘Who am I?’ display by the students, including their names and place and date of birth. Only one student added 음력 before the date, so for high school students of 2008, born in the early 1990s, dates are solar calendar unless otherwise specified. On the other hand, people still generally give their ages in Korean-style; that is, children are born at the age of ‘1’, counting the time in utero. Traditionally, everyone turned the new age on lunar New Years Day (late January/early February). (In the days before printed calendars, it must have been very difficult to keep track of when any given day would fall.) This means that approximately 1/12th of Koreans (those born between 1 January and lunar New Year) have a Korean age 2 years older than their western age (I was going to type ‘real age’, but that is being heliocentric). One of my Korean great-nieces was born in early January, so turned 2 at the age of approximately three weeks, making her one of the oldest in her year western-style, but one of the youngest Korean-style. (And approximately 1 in 365 babies are born on the day before lunar New Year, so turn 2 within hours of their birth.))
(PPS Today (Wed 2 August – I have been drafting this for several days) was the birthday of one of my colleagues. We had a cake and stood around chatting for a while. I spoke to a Korean colleague and gave him a brief precis of all of the above. He said he was born in March, but his lunar calendar birthday of 음력 1월 xx일 became xx January on his birth registration. He is somewhat younger than my wife, so by the time he started school the procedure was more efficient. The school year starts on 1 March, so because his official date of birth is in January, he started that particular year rather than the next, and was therefore a year younger than some of his classmates.)