The band from ten to twenty degrees
At noon on this date the Sun has stood between about fourteen and nine tenths of a degree of Virgo and sixteen and a third, taking every year from 1930 to 2035. Every one of those values falls in the second of the sign's three ten degree divisions.
The divisions are older than the planetary rulers attached to them. Egyptian astronomers used thirty six star groups to mark the hours of the night, each rising about ten days apart, and the scheme was later mapped onto the zodiac as three bands per sign. When Hellenistic writers gave them planetary rulers they were adding a layer to something that had started as a way of telling the time.
Venus in an earth sign
Counting the Chaldean order of planets from the first degree of Aries, this band comes out under Venus. Tradition reads that as Virgo's precision applied to form and proportion, which is why the older texts associate the middle decan with craft, cultivation and the handling of material rather than with pure analysis.
There is a competing assignment. The triplicity scheme distributes a sign's bands among the rulers of the three signs sharing its element, in order, so Virgo's go to Venus, Mercury and Saturn and this one falls to Mercury. Neither scheme is derived from observation. When two inherited conventions disagree about the same ten degrees, the disagreement is the honest answer, and any character sketch built on the band carries that uncertainty with it.
Why the sign never wavers
Virgo runs from one hundred and fifty to one hundred and eighty degrees of ecliptic longitude. The Sun reaches the first of those around 22 or 23 August and the second around 22 or 23 September, with the exact instants shifting by a few hours a year and jumping back at every leap day.
Eight September sits about a fortnight inside that stretch on both sides. No shift of that size can reach it, so unlike dates at the ends of a sign, this birthday needs no birth time and no time zone to settle the sun sign. The certainty is real, and it is also the reason a page that only tells you the sign has told you almost nothing.
The rest of the chart is still open
The Moon covers around thirteen degrees a day, so it changes sign every two and a half days and this date allows two possibilities, sometimes three. The rising sign is undetermined altogether without an hour, since the whole zodiac passes the eastern horizon in a day.
Mercury and Venus stay close to the Sun and so are usually in Virgo, Leo or Libra on this date, but which of those depends on the year. The outer planets depend on the decade rather than the day. All of this is why a birth chart asks for the time and place, and why the widget above wants your year before it will give you a degree instead of a range.
Put plainly, the date fixes one placement out of a dozen. That is enough to put you in a category with everyone born in the same fortnight, and not nearly enough to describe a chart.
Questions people ask about this
What decan is 8 September?
The second decan of Virgo, from ten to twenty degrees. The Chaldean order assigns it to Venus, though the triplicity scheme gives the same band to Mercury.
Is 8 September ever a sign other than Virgo?
No. The date sits about two weeks inside Virgo, far beyond the few hours of variation the sign boundaries show from year to year.
What is the solar degree on 8 September?
Between roughly fourteen and nine tenths and sixteen and a third degrees of Virgo at noon, across the last century. The precise figure depends on your year, hour and birthplace.
Why do sources disagree about the decan ruler?
Because two schemes survive from different traditions and neither is settled by observation. The Chaldean order counts planets by speed, and the triplicity method groups signs by element.
Does the decan matter more than the sign?
It is a narrower description, so it distinguishes birthdays that share a sign. Tradition treats it as qualifying the sign rather than outranking it.
Can I get my full chart from this date alone?
No. The date fixes the Sun and roughly locates Mercury and Venus. The Moon needs the hour to be certain, and the rising sign and houses need the hour and the place.