Jimin's birthday is 13 October, and 25 other Korean stars share it — day 137 of 366

Fans have started organising around 13 October, the birthday of BTS’s Jimin, weeks ahead of the date. We hold full birth dates for 9,249 Korean entertainers, so the question of whether that date is special is one we can answer by counting rather than guessing.

It is not special. 26 people in our panel share it — Jimin and 25 others. The average calendar day holds 25.27. Ranked against all 366 days, 13 October comes 137th.

That is a finding worth publishing precisely because it is dull. A date matters to the people who care about it, and no amount of counting changes that; what counting can do is stop anyone claiming the calendar itself is unusual there.

The months are not even, though

February holds 40% more birthdays per day than June. Months are compared per day here, not by total, because February has the fewest days and a raw count would make it look empty.

Two of the busiest days are artefacts, and we can name them

These are the busiest single days in the panel:

1 January is not a real cluster. When only a birth year is known, editors sometimes record 1 January, so that date collects people whose actual birthday is unknown. 28 February sits at exactly the same height, which is the sort of coincidence that deserves suspicion rather than a paragraph of explanation.

So we ran the test that matters: delete every day above 1.5 times the average — five days, 218 people — and re-count. February stays first at 29.08 per day, June stays last at 21.80. The threshold chose which days to drop, not us, and the ranking does not depend on the suspicious ones. That is the only reason we are willing to print it.

Our own day page says 18, and that is not a contradiction

We already publish a page for 13 October. It says 18, not 26.

Both numbers are right, because the panels are different and the difference is the point:

The day pages rank each date’s names by how much they are read, so they can only list people who have an article to read. This calendar count does not rank anybody, so it can include people who have a birth date and nothing else.

We are printing both rather than quietly aligning them, because a reader who finds 18 on one of our pages and 26 on another is entitled to be told which is which — and because a house that silently harmonises its own numbers cannot be checked from outside.

Our own two counts disagree, and that is the honest headline

We published a birthday page earlier built on 1,317 group members. It found March fullest and July thinnest. This panel of 9,249 entertainers finds February and June.

Same method, same source, different panel, different answer. Neither is wrong; they are answers to different questions — one about idol group members, one about Korean entertainers broadly. What it means practically is that anyone quoting “the month with the most K-pop birthdays” should say which panel they mean, because the two do not agree.

We could have quietly retired the older number. Publishing both is more useful, and it is also the more accurate description of what we know.

What this is not

Not a prediction and not a claim about any person. A birth date on Wikidata is what editors recorded.

Not a complete panel. People with only a birth year recorded are excluded rather than placed on 1 January, which is the mistake this article is partly about.

Not an explanation. Birth seasonality, school-entry cutoffs and who ends up with a Wikidata entry at all would each produce a February peak. We cannot separate them and do not try.

Month-by-month tables, including the version with clustered days removed, are on K-pop idol birthdays by month.

This is a count of public records. It is a statistic, not a statement about any individual.