The sign, briefly
Aquarius. The date sits about ten days before the Pisces boundary, which the year to year drift of roughly a day cannot close, and nearly three weeks after the Capricorn one. No year in the modern calendar puts it elsewhere.
That is the entirety of what most pages on this date offer, and it is the least individual fact available, shared with everyone born across a month.
A decan line within reach
At noon from 1930 to 2035 the Sun on 8 February has fallen between 18.6 and 20.0 degrees of Aquarius. The decan boundary sits at exactly twenty, so the latest years in that range arrive at it.
Two things push the position around. The first is the slow forward drift of about a degree a century, caused by the leap year rule overcorrecting very slightly for the quarter day the tropical year runs long. The second is the four year wobble within the cycle, which spans about three quarters of a degree. Add the birth hour, worth up to half a degree either way, and a birth in a recent late-drifting year can land on either side.
This is the sort of question the widget above exists for. It uses your year, hour and birthplace rather than assuming noon, so it names your decan instead of estimating it.
It is also worth knowing why the range ends exactly at twenty rather than passing it. The figures here run to 2035, and the drift is slow enough that the line is only just being reached at the end of that span. Births later this century on this date will sit past it at noon more often than not.
What differs across the line
The second decan of Aquarius, ten to twenty degrees, takes Mercury in the Chaldean order and Gemini under the triplicity scheme, which is also Mercury. Both schemes agree.
The third decan, twenty to thirty, takes the Moon in the Chaldean order and Libra, and so Venus, under the triplicity scheme. The schemes disagree, so anyone landing above twenty degrees will find the ruler quoted differently in different places depending on which system the writer used without saying so.
Tradition reads the Mercury band as adding description and comparison to the sign, and the third band as softening it toward the social and the reflective. Both are interpretations the tradition carries.
The general lesson is that boundaries in astrology are instants rather than zones. A position is on one side or the other, and the appearance of a blend is usually the appearance of missing information about the year, the hour or the place of birth.
Everything else still needs your details
The Moon changes sign every two and a half days or so and can do it during 8 February itself, so the hour usually decides it. The Ascendant moves through the full zodiac in a day and depends on latitude as well as time, and the houses follow from the Ascendant.
So this date settles one placement and puts a genuine question mark over a second, which is one more open question than most birthdays offer. Both are answerable from a year, an hour and a place.
Precession is sometimes raised at this point, since the equinox drifts against the fixed stars by about a degree every seventy two years. It does not affect these figures, because tropical astrology measures from the equinox itself. It is the reason a sidereal calculation would give a different answer entirely.
Questions people ask about this
What sign is 8 February?
Aquarius, in every year. The Pisces boundary is about ten days away and the year to year drift is only about a day, so it is never in play here.
Which Aquarius decan is 8 February?
Usually the second, but not always. The noon degree runs from about 18.6 to 20.0 across the last century, and the decan line is at twenty, so the most recent years reach it.
Does my birth hour change the decan on this date?
In a borderline year, yes. The Sun moves about a degree a day, so a morning birth and a late evening birth differ by roughly half a degree either side of noon.
Who rules the third decan of Aquarius?
The Moon in the Chaldean order. The triplicity scheme instead assigns it to Libra and so to Venus, which is a real disagreement between the two systems.
Why do the schemes agree on one decan and not the other?
They are built on unrelated logic. The Chaldean order runs a fixed planetary sequence through all thirty six decans, while the triplicity scheme distributes each sign's decans among signs of the same element. Where they coincide it is coincidence.
Is a decan boundary as important as a sign boundary?
Less so. A sign boundary changes the sign, which is the headline placement. A decan boundary changes a shading within the sign, and the tradition treats it as a refinement.