The most common birthday in Australia
The top dates are close together in the model. That means the first-place result belongs to a seasonal cluster, not a date that is dramatically busier than every neighboring day.
Compare another country
Changing the country updates the direct answer, top 10 list, percentages, and seasonal summary.
The 10 most common birthdays in the Australia model
The list is ordered from the highest modeled daily percentage downward. These dates receive the lowest birthday-rarity scores.
August 31
0.332% of birthdays in the model, about 3.32 per 1,000. That is 21.4% above the average calendar date.
This date sits inside the late-August and early-September peak built into the current model.
Check August 31 in the calculatorSeptember 1
0.332% of birthdays in the model, about 3.32 per 1,000. That is 21.4% above the average calendar date.
This date sits inside the late-August and early-September peak built into the current model.
Check September 1 in the calculatorAugust 30
0.331% of birthdays in the model, about 3.31 per 1,000. That is 21.1% above the average calendar date.
This date sits inside the late-August and early-September peak built into the current model.
Check August 30 in the calculatorAugust 29
0.330% of birthdays in the model, about 3.30 per 1,000. That is 20.9% above the average calendar date.
This date sits inside the late-August and early-September peak built into the current model.
Check August 29 in the calculatorSeptember 2
0.330% of birthdays in the model, about 3.30 per 1,000. That is 20.8% above the average calendar date.
This date sits inside the late-August and early-September peak built into the current model.
Check September 2 in the calculatorAugust 28
0.330% of birthdays in the model, about 3.30 per 1,000. That is 20.7% above the average calendar date.
This date sits inside the late-August and early-September peak built into the current model.
Check August 28 in the calculatorAugust 27
0.329% of birthdays in the model, about 3.29 per 1,000. That is 20.4% above the average calendar date.
This date sits inside the late-August and early-September peak built into the current model.
Check August 27 in the calculatorAugust 26
0.328% of birthdays in the model, about 3.28 per 1,000. That is 20.2% above the average calendar date.
This date sits inside the late-August and early-September peak built into the current model.
Check August 26 in the calculatorSeptember 3
0.328% of birthdays in the model, about 3.28 per 1,000. That is 20.2% above the average calendar date.
This date sits inside the late-August and early-September peak built into the current model.
Check September 3 in the calculatorAugust 25
0.328% of birthdays in the model, about 3.28 per 1,000. That is 20.0% above the average calendar date.
This date sits inside the late-August and early-September peak built into the current model.
Check August 25 in the calculatorHow the busiest birthdays compare across six countries
The current models place their busiest dates around the transition from August to September. The exact first-place date varies slightly by country.
| Country | Most common date | Modeled frequency | Busiest month |
|---|---|---|---|
| United States | September 1 | 0.333% | August |
| Canada | August 31 | 0.333% | August |
| United Kingdom | August 31 | 0.332% | August |
| Australia | August 31 | 0.332% | August |
| New Zealand | September 1 | 0.332% | August |
| Ireland | August 31 | 0.332% | August |
Why the busiest dates form a cluster
The current models assign their strongest daily values to late August and early September. Neighboring dates receive similar percentages, producing a broad busy period rather than one extreme peak.
That is why a top-10 list is more useful than a single date. The first-place result may shift between August 31 and September 1, while the larger seasonal pattern remains the same.
What a common birthday means
A common birthday is a date with a higher modeled frequency than most other dates. It does not make the birthday less meaningful, and it does not say anything about the personality or individuality of people born on that day.
The full-year average in the Australia model is 0.273% per date. For comparison, February 29 sits at the rare end of the same 366-date table.
Most common birthday questions
What is the most common birthday?
In the current Australia model, August 31 ranks as the busiest date.
What is the busiest birthday season?
The model's highest daily values cluster around late August and early September.
Are the top birthdays identical in every country?
No. The broad seasonal pattern is similar, but the exact order and percentages can change.
Why does a common birthday receive a low rarity score?
The score rises toward the rare end of the ranking, so dates at the busy end receive lower scores.