The middle of a sign
A sign spans thirty degrees, so fifteen is its exact centre. Noon on 5 March, across every year from 1930 to 2035, has placed the Sun between roughly fourteen degrees and fifteen point four degrees of Pisces, which means the position straddles that midpoint depending on the year.
Older traditions treat the middle degrees of a sign as the part where its qualities are least mixed with anything on either side. That is a description rather than a measurement, but the underlying geometry is real: a Sun here is around fifteen days from the previous ingress and fifteen from the next.
It also means the answer depends on the year rather than on the date alone. Two people who share this birthday can sit on opposite sides of the fifteen degree mark, one just inside the first half of the sign and one just into the second.
Why the figure is so consistent
The whole range across more than a century is under a degree and a half, and the leap year rule is why. The tropical year is about a quarter of a day longer than a calendar year of whole days, so the solar position on a fixed date creeps forward through three common years and then drops back when February gains a day.
The net effect is a small oscillation. It also means the exact figure depends on where a birth year sits in that four year cycle, which is one of the reasons a calculated position is more informative than a published range.
The decan and its ruler
The middle band of Pisces runs from ten to twenty degrees, so this date falls in it comfortably. The Chaldean order gives that band to Jupiter, the traditional ruler of the sign, which is why the tradition describes it as Pisces at its broadest rather than its most disciplined or its most pointed.
The decan is the layer that separates one Pisces birthday from another, and almost no birthday page mentions it. Nothing about it changes the sun sign. It refines where inside the sign the Sun sits, and it attaches a second planetary flavour to that stretch.
The triplicity method, which distributes the decans of a sign among the signs of its element, gives this band a different ruler. That is a genuine disagreement inside the tradition rather than an error in one source or the other.
What still depends on the hour
The Moon changes sign every two or three days, so it may be in either of two signs across a single 5 March, and only the birth time settles which. The rising sign is set by the time and latitude of birth and can be any of the twelve, with a new one taking over roughly every two hours.
That is worth repeating because it is the part popular astrology leaves out. The sun sign is shared with everyone born in the same month and is the broadest stroke in a chart. The widget above gives your own exact solar degree from your year and birthplace, along with the distance to the nearest sign boundary, which on this date is about as wide as it gets.
None of that is a reason to distrust what the date does fix. A solar degree computed from a birth record is as checkable as any other astronomical figure, and it is the part of a chart that survives a missing birth time intact.
Questions people ask about this
What star sign is 5 March?
Pisces, in every year. The Sun sits near the middle of the sign on this date, which is the furthest a position can be from either boundary.
What degree of Pisces is 5 March?
About fifteen. Noon positions from 1930 to 2035 run between roughly fourteen and fifteen point four degrees, so some years fall just short of the midpoint and others just past it.
Which decan is a 5 March birthday?
The second decan of Pisces, from ten to twenty degrees, with Jupiter as its ruler in the Chaldean scheme.
Does the middle of a sign mean anything special?
Some traditions treat the middle degrees as the purest expression of a sign, on the grounds that nothing adjacent is close. It is an interpretive convention rather than a technical rule.
Could my sun sign be wrong on this date?
No. Even a birth record with the wrong hour, or a time zone applied incorrectly, cannot move a position near fifteen degrees across a boundary fifteen degrees away.
What would change if I found my birth time?
The rising sign and the houses would become available, the Moon would be settled if the year was one where it changed sign, and the solar degree would gain a fraction of precision.