Approaching a line without crossing it
At noon across that span, the Sun on 29 April falls between eight point two and nine point six degrees of Taurus. The decan boundary sits at ten degrees. The upper end of the range gets within half a degree of it and never arrives.
That is a genuinely narrow miss, and it is worth stating plainly rather than rounding away. A birth late in the evening on this date in a year at the high end of the range comes closer still, though even then the Sun advances only about a degree per day, so the line holds.
It matters because the decan changes ruler at that point under both of the traditional schemes. A date that gets close without crossing is therefore a clean answer rather than an ambiguous one, which is more than can be said for the day that follows it.
Why the position barely shifts across a century
A calendar year of three hundred and sixty five days is about a quarter of a day short of the Sun's return to the same longitude. The Sun therefore arrives at 29 April roughly six hours later in the orbit each year, and a leap day pulls it back by nearly a whole day every fourth year.
The two effects cancel almost exactly. Over a century the position on this date wanders through a band about a degree and a half wide and never leaves it, which is why a solar degree quoted for a calendar date is a reliable thing to quote at all.
The decan and its two rulers
Nine degrees places this birthday in the first decan of Taurus, the band from zero to ten. The Chaldean sequence of faces, counted unbroken from the start of Aries, gives that band to Mercury. The triplicity scheme, which distributes the decans of each sign among the signs of its element, gives it to Taurus itself and so to Venus.
The tradition reads the first decan as the plainest expression of Taurus, fixed earth under Venus, described as patient and physically grounded. Mercury layered over it is read as adding speed of thought to a slow sign, and Venus layered over it as reinforcing what is already there. Those are readings, not measurements.
The distinction is worth keeping because the position is checkable and the description is not. A solar longitude can be computed and verified; a claim about what Mercury over Taurus does to a person cannot.
What the date does not decide
The Moon moves about thirteen degrees a day, so it changes sign every two and a bit days. A 29 April birth can have the Moon in either of two signs, and the calendar date will never tell you which one. The angles are worse still: the rising sign turns through all twelve signs in a day, so the horizon at birth is completely unconstrained by the date.
This is the case against treating a sun sign as a personality summary. It is one body in one sign, shared with roughly a twelfth of everyone alive. The widget above computes the exact degree for your own year and birthplace and reports the distance to the nearest sign boundary, which is the part a date alone cannot supply. On this date that distance is large, and a large distance is a result in itself.
Questions people ask about this
Can a 29 April birthday ever be Aries?
No. The Sun leaves Aries around 20 April and by the twenty ninth it is eight or nine degrees into Taurus. No year in the sampled range comes anywhere near the boundary.
How close is this date to the second Taurus decan?
Close. The upper end of the range reaches about nine point six degrees against a boundary at ten, so it falls short by roughly half a degree in the most advanced years.
What is the decan ruler for 29 April?
Mercury in the Chaldean order of faces, Venus in the triplicity scheme. Both traditions are old and in use, so the honest answer names the method alongside the planet.
Does the sun sign change with the hour on this date?
No. The Sun covers only about one degree per day, so even a birth at midnight sits nine degrees clear of any sign boundary. The hour matters for the Moon and the horizon instead.
Why do published tables give slightly different degrees?
Usually because they assume noon in a particular time zone, or a particular reference year. The differences are fractions of a degree and vanish once the actual birth moment is used.
Is a Taurus born on this date different from one born in mid May?
In degree and decan, yes. A mid May Taurus sits in a different ten degree band with a different traditional ruler, which is the layer that distinguishes one Taurus birthday from another.