Where the position lands
Taken at noon in every year from 1930 to 2035, the Sun on this date ran from about nine and seven tenths to roughly eleven and a tenth degrees of Cancer. Ten and a half is the middle figure, and the ten degree mark sits near the bottom of that band.
Most of the sampled years therefore fall past ten degrees and a few fall short of it. The sign never wavers, because the nearest sign boundary is more than a week away, but the face is decided by the year rather than by the date.
The pattern within that range is regular rather than random. Each common year moves the value a quarter degree or so further along, and each leap year draws it back by roughly three quarters, so the position climbs for three years and drops on the fourth. Where in that cycle your year sits is what decides the face.
What sits on either side
Under ten degrees the Sun is in the first face of Cancer, given to Venus in the Chaldean order of faces and to the Moon in the triplicity scheme. Over ten it is in the second face, given to Mercury in the Chaldean order and to Mars in the triplicity scheme.
The tradition reads the second face of a water sign under Mercury as more analytical than the sign's own tenor, and under Mars as more forceful. Both are interpretive conventions attached to a band, and neither changes the sign, the element or the domicile ruler.
Why the year moves the answer
A calendar year of three hundred and sixty five whole days is about a quarter day shorter than the orbital year, so each common year finds the Sun a little further along on a given date. The leap day repays the accumulated surplus and pulls the position back.
Over a century that produces a sawtooth about a degree and a half wide rather than a drift, which is why this date keeps landing in roughly the same place. Here that band happens to sit across a face boundary, so the same mechanism that keeps the sign steady leaves the face unsettled.
The layers a date cannot supply
Cancer is cardinal water ruled by the Moon, and the tradition reads it as protective and led by attachment. That description belongs to everyone born in the month, which is roughly one person in twelve, so it is a starting point rather than a portrait.
The Moon may hold either of two signs on this date depending on the hour, and the ascendant may be any of the twelve, since a new sign reaches the eastern horizon roughly every two hours. The widget above computes your exact degree from your year, hour and birthplace, which also settles which face you fell in.
The slow planets are the exception worth naming. Saturn, Uranus, Neptune and Pluto remain in a sign for years, so the birth year alone fixes them. They are shared with everyone born across the same span, which makes them context for a generation rather than a description of an individual.
Questions people ask about this
What sign is a 2 July birthday?
Cancer, at noon in every year sampled from 1930 to 2035. The Sun sits around ten and a half degrees along, comfortably clear of both sign boundaries.
Which Cancer decan is 2 July?
Usually the second, occasionally the first. The noon position ranges from about nine and seven tenths to eleven and a tenth degrees, so the ten degree line falls inside that range.
How do I know which side my birth falls on?
By calculating the position from your year, hour and birthplace. The year does most of the work, since leap years pull the figure back and common years push it on.
What is the difference between the two decans?
The face ruler alone. Venus and the Moon hold the first band in the two schemes, while Mercury and Mars hold the second. The sign, element and domicile ruler are the same either way.
Why does an internal line matter?
Because the face narrows a description from a whole sign to a third of one, with its own ruler. It is the layer that separates one Cancer birthday from another, and most pages omit it.
Does being near the line weaken anything?
No. A position sits in one band at any instant, and there is no traditional technique that treats proximity to a face line as diluting either side.