Void of Course Moon

A period during which the Moon is making no further major aspects to any planet before leaving its current sign, traditionally interpreted as an inauspicious time to start anything new.

A void of course Moon (often abbreviated as VOC) is a period of time during which the Moon is finished forming any major Ptolemaic aspects (conjunction, sextile, square, trine, opposition) with any other planet before it leaves the sign it is currently in. The VOC period begins after the Moon's last aspect and ends when the Moon ingresses into the next sign.

In traditional electional astrology — the practice of choosing a time to begin something — VOC periods are considered inauspicious. Decisions made, events begun, or contracts signed during a VOC Moon are said to "come to nothing", to lack follow-through, or to drift without traction. The traditional advice is to wait until the Moon is in its next sign and forming aspects again before initiating anything important.

The void of course Moon happens daily, with VOC periods ranging from a few minutes to many hours, depending on where the Moon is in its current sign and what aspects remain. A Moon at 28 degrees of a sign with no further aspects has hours of VOC time before it ingresses; a Moon at 5 degrees of a sign with one final trine in its future has only a brief VOC period.

Modern interpretations of VOC vary. Some astrologers continue to treat it as a meaningful timing constraint and avoid major decisions during VOC windows. Others find it overhyped relative to its actual observable effect. ZODIA does not currently surface VOC status in the daily reading, but the underlying ephemeris contains the data and it could be added as a future feature for users who follow electional principles.