Sidereal Sun Sign Dates
Sidereal Cancer Dates
July 17 to August 16
Lahiri (IAE 1985) ayanamsa · approximate dates for 2020 to 2050 · shifts ~1 day per 72 years
In the Lahiri sidereal zodiac, the Sun enters Cancer on approximately July 17 and leaves on approximately August 16. This corresponds to most of what tropical astrology calls Leo. If you were born between roughly July 17 and August 16, your sidereal Sun sign is Cancer.
Why does sidereal Cancer start on July 17?
Sidereal Cancer dates overlap heavily with tropical Leo, creating one of the more dramatic reframes in the sidereal system. The chart ruler shifts from the Sun (tropical Leo's ruler) to the Moon (Cancer's ruler), moving the entire interpretive emphasis from public expression and identity to emotional interior and caretaking instinct. The star Regulus, traditionally called the heart of the Lion, sits near the boundary of sidereal Cancer and Leo; its slow precession across this boundary has been discussed as astrologically significant. The exact ingress date shifts about one day every 72 years.
What if you were born on the cusp?
People born in the last week of tropical Cancer (roughly July 17 to July 22) are in the cusp zone. If you were born in this window, calculate your sidereal chart to confirm whether your sidereal Sun is Cancer or Leo.
Get your complete sidereal chart
The Sun sign dates above are approximate. Your full chart includes Moon, rising, and all planets in the Lahiri sidereal zodiac, plus the exact ayanamsa applied to your birth date.