Dates that change every year
The Sun enters each sign at a slightly different moment every year. These tools calculate those moments from an astronomical ephemeris instead of using fixed tables, so cusp birthdays get a real answer and every sign page lists the exact dates for the coming years.
Twelve signs, four building blocks
Astrology describes each sign through its element, modality, polarity and ruling planet. The same building blocks explain compatibility: they decide which angle two signs form and why some pairs are traditionally called easy and others challenging.
Facts and interpretation
Dates and positions are astronomy. Character descriptions and compatibility readings come from astrological tradition and are meant for entertainment and self-reflection — they make no predictions.