Why does Capricorn change to Aquarius on Jan 20th?

Capricorn transitions to Aquarius around January 20th due to the astrological calendar, which divides the year into twelve signs based on the sun's position relative to Earth. Each sign typically spans about a month, with Capricorn covering December 22 to January 19 and Aquarius starting on January 20. This shift marks the beginning of a new zodiac cycle and reflects changes in energy and characteristics associated with each sign. As the sun moves into Aquarius, themes of innovation, individuality, and humanitarianism become more prominent.