Industry
Part of August birthdays: how calendar conversion works
Athletes born in August, and how the dates are checked
Athletes born in August, from Usain Bolt to Kobe Bryant, and the records offices, league guides and time zone quirks that verify each birth date.
What to take away
A birth date is not a fact until you can name the office that holds it. Athletes born in August show why: their dates come from four countries and three kinds of record.
- Athletes born in August include Usain Bolt, Kobe Bryant, Roger Federer, Tom Brady and Magic Johnson. The list also names Pete Sampras, Sydney McLaughlin-Levrone, Caeleb Dressel and Robert Lewandowski.
- Their dates come from three authoritiesa national vital records office, a league media guide, and a passport or Olympic entry form.
- A birth time near midnight plus a time zone difference can shift a published date by one day.
- Middle initial, birthplace and full legal name separate two athletes who share a surname and a date.
- When two sources disagree, publish both and name each one. Do not pick a winner.
- Marta is often misdated to August. Brazilian civil registry and FIFA profile give 19 February 1986.
The August list
These are the athletes most often looked up, with the date and the source that carries it.
August athletes and date sources
Athlete
- Usain Bolt
- 21 August 1986
- Kobe Bryant
- 23 August 1978
- Roger Federer
- 8 August 1981
- Tom Brady
- 3 August 1977
- Michael Phelps
- 30 June 1985
- Serena Williams
- 26 September 1981
Date
- Usain Bolt
- Jamaican registration
- Kobe Bryant
- NBA media guide
- Roger Federer
- Swiss civil registry
- Tom Brady
- NFL media guide
- Michael Phelps
- Not August
- Serena Williams
- Not August
Source
- Usain Bolt
- Kobe Bryant
- Roger Federer
- Tom Brady
- Michael Phelps
- Serena Williams
| Athlete | Sport | Date | Where the date is held |
|---|---|---|---|
| Usain Bolt | Sprinting | 21 August 1986 | Jamaican registration, carried in World Athletics profile |
| Kobe Bryant | Basketball | 23 August 1978 | NBA media guide, Pennsylvania birth record |
| Roger Federer | Tennis | 8 August 1981 | Swiss civil registry, ATP profile |
| Tom Brady | American football | 3 August 1977 | NFL media guide, California birth record |
| Magic Johnson | Basketball | 14 August 1959 | NBA media guide, Michigan birth record |
| Pete Sampras | Tennis | 12 August 1971 | ATP profile, Washington, D.C. birth record |
| Sydney McLaughlin-Levrone | Track and field | 7 August 1999 | World Athletics profile, New Jersey birth record |
| Caeleb Dressel | Swimming | 16 August 1996 | USA Swimming profile, Florida birth record |
| Robert Lewandowski | Football | 21 August 1988 | FIFA profile, Polish civil registry |
| Michael Phelps | Swimming | 30 June 1985 | Not August; listed to show the check |
| Serena Williams | Tennis | 26 September 1981 | Not August; same reason |
| Marta | Football | 19 February 1986 | Not August; Brazilian civil registry, FIFA profile |
The last three rows are the point. A list built from memory puts Phelps, Williams and Marta in the wrong month, and a list built from a single aggregator copies that error a hundred times.
Who holds the date
A US birth date sits with the state department of health that issued the certificate. It does not sit with a federal office or with the league. Jamaica, Switzerland and Brazil each keep their own civil registry, and each has its own rules on who may request a copy.
The August index collects the month across all four categories. For the January equivalent, see the January birthdays page.
A league media guide is a secondary source. It repeats what the team submitted, and teams submit what the player or agent supplied. That chain is short enough to check, and it is where most published sport dates actually come from.
Where a date moves by one day
A birth at 11:40 p.m. local time on 21 August in Kingston is 22 August in Tokyo. If the record is transcribed in the second zone, the athlete gains a day.
How a date shifts by one day
- Birth at 11:40 p.m. Kingston on 21 August
- Same moment is 22 August in Tokyo
- Transcribed in Tokyo, athlete gains a day
- Day 233 non-leap year is 21 August
- Day 233 leap year is 20 August
- Check issuing office's local clock
The same shift appears when a date is stored as a day-of-year number and converted back without the original zone. Day 233 of a non-leap year is 21 August; in a leap year it is 20 August. One day of drift, no error message.
Check the issuing office's local clock, not yours. If the source gives a time, keep it with the date.
Two athletes, one name
Surname plus initial is the weakest possible key. It is short by design, and sport draws from large populations.
Birthplace, full legal name and middle initial do the separating work. A roster that carries only a surname and an initial cannot be deduplicated safely, which is why governing bodies issue registration numbers.
Data deduplication is the general problem of deciding two records describe one thing. For people, the tie-breaking fields are exactly the ones that collide.
| Tie-breaker | Why it fails |
|---|---|
| Surname plus initial | Common by construction |
| Club | Two players with one name can pass through one club |
| Position | Coarse, and players change position |
| Nationality | Coarse, and dual eligibility is normal |
Split on suspicion, merge on evidence
A split record shows two entries where there should be one. A reader sees the gap and reports it.
A merged record shows one entry holding two careers. It looks complete, so nobody checks it, and the merge has already deleted the source notes that proved the two were different.
Data cleansing is where most bad merges begin, because a cleaning pass runs in bulk and nobody reviews its decisions one at a time. Normalize fields, flag candidates, and leave the merge to a person.
Two rules keep it safe: a cleaning step never deletes a source reference, and it never merges entities. The April musicians page shows how one name becomes several spellings no string comparison will reconcile.
When two sources disagree
Do not resolve it. Publish both dates, name each source, and say what would settle it. A reader who sees "state health department says 21 August, league guide says 22 August" can weigh that. A reader who sees one confident date cannot.
The January athletes page covers what a sports entry should record so any claim can be traced back. The actors with late-year birthdays page covers the same trace for screen credits.
Copyright and publicity rights limit how much of a record you may republish, and those rules vary by jurisdiction. Name the statute, then talk to a licensed attorney. Do not request a sealed or restricted record yourself; the issuing vital records office states who is eligible.
Common questions
Why does the same athlete show two birth dates?
Usually a time zone shift on a birth near midnight, or a day-of-year conversion that ignored leap years. Occasionally it is two different people with one name. The fix is to name both sources and the office that issued each.
Can I get a birth certificate to confirm a date?
Only if you meet the issuing office's eligibility rules. Each state health department and each national registry sets its own. For most readers the league media guide or the federation profile is the practical source, and it is checkable.
What should a sports entry record?
Full legal name, date with its source, birthplace, and any registration number the governing body issued. Those four fields separate two athletes who share a surname, and they let a reader trace the date back.
How do I report a date that looks wrong?
Give the entry, the date you believe is correct, and the source you checked. Two disagreeing sources are more useful to an editor than one confident claim.
