Rihanna has never shared a birth time publicly. Rihanna was born on 20 February 1988 in Saint Michael, Barbados, and that date is enough to settle a Pisces Sun and an Aries Moon. The Moon spent the whole day in Aries alongside Venus and Jupiter, so three planets in the sign of courage are certain at any hour.
Only one birth time for Rihanna gets passed around, and its trail is short. The figure is 8:50 am, and it comes from IMDb trivia that is no longer online. No interview, post or birth record behind it has ever surfaced. Astro-Databank gives it a C, the grade for a time quoted without a known source, and Astrotheme rates it the same way.
That doesn't make 8:50 wrong. It means nobody can yet show where the number started, so it is best held lightly. Fans who keep it in circulation are doing what fans do, keeping a light on in case the real answer arrives.
The Sun sits in the opening degrees of Pisces, the sign of imagination and empathy, which reads a room and turns feeling into music. It makes easy sextiles to Saturn and Uranus, a meeting of discipline and invention at the very start of Capricorn, with Mars in late Sagittarius just behind them. Put together, that is ambition that likes to rewrite the rules and then build something solid on the new ones.
The Aries Moon is bold, fast and honest about what it wants. Venus sits right beside it, so heart and taste move as one, and Jupiter in Aries adds confidence and an appetite for risk. Mercury in Aquarius, retrograde, gives an original, independent mind that circles back to refine an idea until it lands, and a square from Pluto in Scorpio lends it focus and a talent for getting to the core of a thing.
A real birth time would add the rising sign, the Midheaven and the houses, which change every few minutes. If 8:50 am were right, it would put the rising sign in Aries, joining the Moon, Venus and Jupiter in one fiery sign. Jupiter would fall in the 1st house, the Moon and Venus in the 12th just above the horizon, and the Midheaven in Capricorn near Saturn and Uranus.
That would be a striking chart, but it hangs on one unsourced line. An hour earlier, 7:50 am, would put the rising sign in Pisces instead, and an hour later, 9:50 am, would put it in Taurus. Until a record turns up, 8:50 stays one possibility among many.