Two kinds of boundary
Boundary talk around birthdays usually means sign boundaries, where the Sun crosses from one thirty degree block into the next. Those are the ones that produce arguments, and this date is far from any of them. The Leo edge is more than a week behind and the Libra edge three weeks ahead.
The smaller boundaries inside a sign get no attention at all. Each sign has two of them, at ten and twenty degrees, dividing it into faces. On 1 September the Sun sits just short of the first of Virgo's, which makes this an unusual date in a quiet way.
Traditional practice does not treat the internal boundaries as dramatic. Crossing one changes the face ruler and leaves the sign, the element, the mode and every aspect exactly as they were, which is why they attract so little argument compared with the sign edges.
Nine degrees, and the ten degree line
Noon positions on 1 September have run between about 8.1 and 9.5 degrees of Virgo across the whole span from 1930 to 2035. Every one of those values is inside the opening face, but the top of the range is only half a degree short of the line, which the Sun reaches around midday on the following date.
Since the Sun covers a little under a degree per day at this point, and since a birth in the late evening in an eastern time zone sits many hours later in universal time than one in the early morning in the Americas, the practical distance from the face boundary varies. It stays on the near side of it, but not by much.
It is a quieter fact than a sign change, but it is a real one, and it is measurable.
What the first face carries
The opening decan of Virgo runs from the start of the sign to ten degrees. The Chaldean order, looping Mars, Sun, Venus, Mercury, Moon, Saturn and Jupiter from the beginning of Aries, gives it to the Sun. The triplicity order, walking the earth signs in the sequence Taurus, Virgo, Capricorn, gives it back to Virgo and so to Mercury.
Traditionally the face colours the sign's reading rather than overruling it. Virgo remains mutable earth under Mercury, described as methodical and corrective, and the solar face is read as putting that work somewhere visible. It is an old interpretive layer and nothing about it is a forecast.
The date does not carry a chart
The solar degree is the only placement the date fixes. The Moon travels roughly thirteen degrees a day, so on any 1 September it lies in one of two signs, and only the hour and the year say which. The Ascendant depends on the Earth's rotation, so all twelve signs are in play and the answer changes about every two hours.
That makes the Sun sign the least individual thing anyone born on this date has. It is shared with everyone else born on it, and with a good many people born on the days either side. The widget above takes the year, the hour and the birthplace and returns the exact longitude, along with how far that fell from the nearest sign boundary.
Questions people ask about this
What sign is 1 September?
Virgo, settled in every year and every time zone. The Sun entered the sign in late August and does not reach Libra until the back end of September.
Which decan does 1 September fall in?
The first face of Virgo, but near its end. Noon positions run from about 8.1 to 9.5 degrees, and the second face starts at ten, so the Sun is close to the line without crossing it.
Could my Sun be in the second decan?
On this date, no. The whole range across the last century stays below ten degrees. A birthday one day later straddles the line and genuinely depends on the year.
Does the decan boundary matter as much as a sign boundary?
Less. Crossing it changes the traditional face ruler and nothing else. A sign boundary changes the sign, its element, its mode and its ruler all at once.
What else does my birth date tell me?
It narrows the Moon to one of two signs, which is real but not usable without the hour. It tells you nothing about the Ascendant or the houses, which need the time and the place.
How exact is the solar degree?
Given the year, the local birth time and the coordinates of the birthplace, it can be computed to minutes of arc. Without a time the calculation defaults to noon, which on this date is accurate to within about half a degree.