The measurable part first
Aquarius, in every year. The date sits well over a fortnight past the Capricorn boundary and about twelve days short of Pisces, so nothing about the year or the hour disturbs it.
At noon across 1930 to 2035 the solar degree has run from 16.6 to 17.9. The spread is small because the leap day compensates almost exactly for the quarter day the tropical year runs long, so a calendar date keeps returning to nearly the same point on the orbit. The residual is about a degree per century.
The degree is worth writing down even when the sign is obvious, because it is the figure every later technique needs. Aspects, decans and any progression of the Sun all start from the degree rather than from the sign name.
Two rulers for one sign
Before Uranus was found in 1781, every sign had a ruler drawn from the seven visible planets, and Saturn took both Capricorn and Aquarius. That is the traditional scheme and it is internally complete: the two signs opposite the Sun and Moon go to Saturn, the next pair out to Jupiter, and so on.
Modern practice reassigned Aquarius to Uranus on the grounds that the new planet's character matched the sign better than Saturn's did. Most contemporary writing uses that assignment, and much traditional and Hellenistic work keeps Saturn.
The difference is not cosmetic. A Saturn-ruled Aquarius is read as structural, bound by its own rules and slow to abandon a position. A Uranus-ruled one is read as disruptive and given to breaking the pattern. Both readings circulate under the same sign name, which is one reason Aquarius descriptions vary so much between sources.
A reasonable working position is to hold both. Saturn is the traditional ruler and remains the one that makes the older technical machinery work, since dignity, sect and the rest were all built around the seven visible planets. Uranus is the modern addition and carries most of the popular description. Neither cancels the other, and many practising astrologers cite both.
The decan under it
Seventeen degrees sits in the second decan, ten to twenty. Mercury rules that band in the Chaldean order, and the triplicity scheme assigns it to Gemini, so both point to Mercury. Whatever you make of the Saturn and Uranus question, the decan ruler here is not in dispute.
Tradition reads that Mercury band as adding articulation and an interest in comparison to whatever the sign already carries. It is the layer that separates one Aquarius birthday from another, and it is the layer almost no birthday page bothers with.
What the date does not fix
The Moon crosses a sign roughly every two and a half days and can change during 6 February itself, so its sign needs the hour in most years. The Ascendant runs through the whole zodiac in a day and depends on the latitude of birth as well as the time, and every house position follows from it.
The widget above computes the solar degree from your own year, hour and birthplace and reports the distance to the nearest sign boundary, which on this date is large.
The degree also does interpretive work in its own right, since aspects between planets are measured in degrees. Two Aquarius Suns a week apart in birth date sit five degrees apart and can make quite different contacts with the rest of a chart.
Questions people ask about this
Is Aquarius ruled by Saturn or Uranus?
Both, depending on the scheme. Saturn is the traditional ruler and held the sign alone before Uranus was discovered. Modern practice usually gives the sign to Uranus, and many astrologers cite both.
What sign is 6 February?
Aquarius in every year. The date sits far from both neighbouring boundaries, so no combination of year, hour or time zone changes the answer.
What degree of Aquarius is 6 February?
Roughly 16.6 to 17.9 degrees at noon across 1930 to 2035. The widget above returns a single figure once it knows your year, hour and birthplace.
Does the choice of ruler change the sun sign?
No. The sign is decided by longitude alone. The ruler affects how the sign is interpreted and which planet an astrologer would look to when reading it.
Which decan applies on this date?
The second decan of Aquarius, ten to twenty degrees. Its Chaldean ruler is Mercury and the triplicity scheme assigns it to Gemini, which Mercury also rules.
Why do Aquarius descriptions vary so much online?
Largely because of the split rulership. Writers working from Saturn describe a structured, rule-bound sign, and writers working from Uranus describe a disruptive one, both under the same name.