Astrology houses

Astrology houses divide the chart relative to the local horizon and meridian. Their cusps depend on birth time, location, and the chosen house system.

The Ascendant begins the first house in many systems; the Midheaven is an important angular point. House systems can place cusps differently, so a chart should identify its method.

When birth time is unknown, houses and angles cannot be stated reliably. Planetary signs may still be calculated while house placements are left unassigned.