The Moon void of course

The void-of-course Moon — written “void of course”, or simply v/c, in most ephemerides — is the stretch between the Moon's last exact major aspect and her entry into the next sign. While the Moon travels through a sign, she has time to talk things over with the Sun and the planets: conjunction, sextile, square, trine, opposition. Once that last contact has happened and several degrees still remain to the sign boundary, the Moon is left on her own: the course is finished, and the new one has not begun.

The idea comes from Hellenistic astrology and lived above all in horary practice — the branch in which an astrologer answers a specific question from the chart of the moment it was asked. A question put while the Moon was void of course was held to have “no development”: there is no aspect through which the story could continue. Hence William Lilly's famous remark that with the Moon void of course a matter rarely comes to anything. In modern practice the rule migrated out of horary and into everyday planning.

A period lasts anywhere from a few minutes to a day and a half. The spread is enormous, and it depends not on the Moon's “strength” but on where the planets happen to stand. If a slow planet — Saturn, Uranus, Neptune, Pluto — sits in the last degrees of its sign, the Moon manages an aspect to it right up against the boundary, and the period comes out short. If the planets are bunched in the first degrees of the signs, the last aspect happens early and the Moon runs “empty” for half a day or longer. The periods repeat roughly every two and a half days — the time the Moon spends in one sign.

What people actually do with this. The classic advice: do not start anything new — do not sign, do not launch, do not make the first approach, do not buy anything important — but do calmly carry on with what is already under way: routine, finishing touches, tidying, rest, sleep. This is neither a ban nor a promise of failure. The logic is different: a new undertaking has no follow-up aspect, so it is more likely to fizzle out than to blow up. Plenty of modern astrologers consider the rule excessive for everyday matters and keep it only for important starts.

How the table below is calculated. We take the Moon's major aspects to the Sun and the nine planets — from Mercury to Pluto — find the moment of the last exact aspect before the sign change, and treat that as the start of the period; the end is the minute the Moon enters the next sign. Different schools produce slightly different tables: count only the classical planets out to Saturn and the periods come out longer, add Chiron and Lilith and they come out shorter. We use the set adopted by most modern software.