Seventy and thirty six
Neither answer here is an edge case. A third of the years in the run put the Sun still in Leo at noon on 23 August, and the rest have it in Virgo. Two people born on this date a decade apart can be different signs and both be correctly informed.
The split comes from a boundary that never settles. Because the tropical year is longer than the calendar year by close to a quarter of a day, the moment the Sun reaches one hundred and fifty degrees of ecliptic longitude arrives about six hours later each year, then jumps back roughly eighteen hours when February gains a leap day. Follow it down a decade and it covers about a day and a half. Twenty three August sits squarely inside that travel, which is why the answers alternate rather than cluster. The tally is a description of where the boundary has been, not a probability anyone can apply to a particular birth.
The hour and the meridian
Knowing the year narrows it but does not close it. The ingress happens at a particular hour, and a birth on either side of that hour on the same date falls on opposite sides of the line. On this date a birth at breakfast and a birth at supper can genuinely differ.
Then there is the birthplace. The ingress is one global instant and only the local reading changes, so an entry into Virgo at 04:00 UTC on 23 August is still midnight on the twenty second in Chicago and lunchtime on the twenty third in Bangkok. Reading a sign off the calendar date alone assumes a time zone, usually not yours, and that assumption is the most common cause of a sun sign being reported wrongly. The fix costs nothing beyond naming the town on the certificate.
No mixture is available
Because the split is real, this date attracts more cusp talk than most, with descriptions promising showmanship tempered by precision. The Sun does not offer a tempered state. It occupies one longitude at any instant, either short of one hundred and fifty degrees or beyond it, and two hours either side of the change the placement is wholly one sign or wholly the other.
What cusp actually names is an unresolved record. It marks a birth whose year, hour or place was never checked, and it has no meaning once those are known. The widget above closes that gap from your own details and reports how many hours from the boundary the birth fell. A birth an hour from the change is placed as firmly as one in the middle of a sign.
Fixed fire and mutable earth
Leo is fixed fire ruled by the Sun; Virgo is mutable earth ruled by Mercury. No shared ruler softens the pairing, and the formal categories put them at a distance: one holds a position and wants it seen, the other adjusts constantly and prefers not to be looked at while working.
The received descriptions overdo the gap all the same. Both signs are read as caring about craft and about doing a thing properly rather than approximately, and both are notably hard on themselves when the result falls short. The visible difference is in whether the standard is announced or kept private.
If the calculation gives you the sign you were not raised on, little of substance moves. The Sun is one placement among many, and the Moon, the Ascendant, the planets and the house divisions are entirely unaffected by which side of this boundary your birth landed on.
Questions people ask about this
Is 23 August Leo or Virgo?
Both occur. At noon between 1930 and 2035 the date gave Virgo in seventy years and Leo in thirty six, so about a third of birthdays on this day are Leo. Only a calculation for your own year and place will say which.
Why is this date split so unevenly rather than half and half?
Because the boundary drifts across a window of roughly a day and a half and 23 August sits off centre within it. The date catches the later part of the window more often than the earlier part.
Do I need my birth time?
On this date it genuinely helps. In many years the ingress falls during 23 August itself, so a morning birth and an evening birth on the same day come out as different signs.
Am I a Leo Virgo cusp?
No such placement exists. The Sun sits at one ecliptic longitude at every instant, inside one sign. Cusp describes missing information about the birth rather than a mixed condition.
Why do published date ranges disagree about this day?
Because they flatten a moving boundary into a fixed date and each publisher rounds it differently. Older ranges were also computed for a single time zone and reprinted without adjustment.
Does the rest of my chart depend on this?
No. Only the sun sign is in question. The Moon, the Ascendant, every planet and every house placement are calculated the same way whichever answer comes back.