Sun signs and the dates that decide them
Your sun sign comes from the position of the sun on the day you were born. Because the boundaries shift slightly from year to year, anyone born within a day of a cusp should check a birth chart rather than a date table. The sun and moon sign calculator explains where the edge falls for your date.
The zodiac library covers each of the twelve signs in depth, including elements, modalities and rulerships.
Moon signs and why time of birth matters
The moon moves through a sign in roughly two and a half days, so a moon sign calculated without a birth time is an approximation and we label it as one. With a time, the result narrows considerably.
If the moon interests you more than the sun, the moon phase library and the moon calendar cover phases and dates in detail.
Other zodiac systems
Chinese astrology assigns an animal and an element by year, Mayan and Celtic systems work from different calendars again, and none of them map neatly onto western signs. Running the same birth date through several is a good way to see how differently each tradition slices time.
For readings that change day to day, the daily horoscope covers all twelve signs.