Cusp
Glossary · Last updated: 2026-07-26
A cusp birthday falls near the day the Sun (or Moon) moves from one sign to the next. The exact switch time varies by year and time zone.
You are not two sun signs at once in standard Western astrology, the Sun occupies one sign at your birth instant. Uncertainty means verify the ephemeris.
Our boundary notices
When your birth date sits within a few days of a sign change, we show an as-of notice so you can confirm with birth time if needed.