Length: 30 days (Dec 21 - Jan 19)
Rulers: Saturn (day) & Uranus (night)
Detriment: Moon (day & night)
Tropical or solar zodiac is basically the same every year and is aligned to the seasons. Sidereal zodiac shifts and is how the stars appear in the sky at a given moment. Your true sign is the sidereal one and may or may not match the tropical zodiac.