January 21 Birthday: Zodiac Sign, Birthstone & How Rare It Is

January 21 falls under Aquarius ♒, the Air sign that runs from January 20 to February 18. It sits on the Capricorn–Aquarius cusp: the day the Sun changes sign moves by a day from year to year, so someone born on January 21 in some years is a Capricorn. A birth chart with your birth year, time and place settles it.

January 21 ranks #302 of 366, so it is less common than most. From 1994 to 2014 an average of 10,866 babies were born in the US on January 21, against 11,175 on an average day.

The birthstone for January 21 is Garnet, the stone for January. The birth flowers are carnation and snowdrop.

It depends on the year — and for January 21 also on when Lunar New Year fell that year, because the Chinese zodiac year starts in late January or February, not on 1 January. The table above shows the right animal for every year.

In the US, 9 September is the most common birthday, closely followed by other mid-September dates such as the 19th, 12th and 17th — about nine months after the end-of-year holidays. The data is the CDC and Social Security Administration count of every US birth from 1994 to 2014.

29 February, since it only comes round in leap years. Among the dates every year has, 25 December is the rarest, followed by 1 January, 24 December, 4 July and 2 January: far fewer births are scheduled (inductions and planned caesareans) on holidays.

The Chinese zodiac year starts at Lunar New Year, which falls between 21 January and 20 February, not on 1 January. If you were born in January or early February before that year’s Lunar New Year, your animal is the one for the year before. This report checks the actual Lunar New Year date for your birth year.

A cusp is the day or two when the Sun moves from one sign into the next. The exact day shifts from year to year, so someone born on a cusp date can be either sign depending on their birth year and time. A full birth chart with your time and place of birth settles it.

This report uses the Pew Research Center ranges: Silent Generation 1928–1945, Baby Boomers 1946–1964, Generation X 1965–1980, Millennials 1981–1996 and Generation Z 1997–2012. For Generation Alpha (2013–2024) and Generation Beta (2025–2039) it uses the commonly cited ranges, since Pew has not set them. Other sources draw the lines a year or two differently.

No. The report is worked out when the page loads and nothing is saved. A report link contains the date, so only share it with people you are happy to tell your birthday.