Moon Phase Today: Current Lunar Phase Plus the Full 2026 Calendar

One complete lunar cycle — from new moon back to new moon — takes about 29.53 days. This is called the synodic month, and it is the cycle most lunar calendars track. It is slightly longer than the 27.32-day sidereal month (the Moon's orbit relative to the fixed stars) because Earth is also moving around the Sun: by the time the Moon has finished one orbit, the Sun has shifted a little, and the Moon has to travel a bit further to return to the same alignment.

The phases are a matter of geometry. The Sun lights one hemisphere of the Moon at all times — the Moon is never "half dark" in any absolute sense. What changes is our viewing angle. At new moon, the Moon sits roughly between the Earth and the Sun, so the lit hemisphere faces away from us. At full moon, the Earth is between the Sun and the Moon, so the lit hemisphere faces us directly. Between those two extremes, we see a growing or shrinking slice of the illuminated side.

There is no "dark side of the Moon" in the literal sense. The far side of the Moon (the side that always faces away from Earth, because the Moon is tidally locked) receives just as much sunlight as the near side, on average. What we call the dark side of the Moon during a new moon is simply the side we cannot see.

In horary and electional astrology, the Moon is said to be void of course when it has finished making all its major aspects (conjunction, sextile, square, trine, opposition) with the other classical planets before leaving the sign it is currently in. The Moon spends roughly two and a half days in each zodiac sign, and during the final hours of that transit — once the last aspect has perfected — it is "running on empty" until it ingresses into the next sign.

Tradition is fairly conservative about void-of-course periods. The classical advice, from sources like William Lilly's Christian Astrology, is that "nothing will come of the matter" — so it is read as an unfavourable window for starting anything important: signing a contract, launching a business, asking a serious question, beginning a journey. Routine work and reflection are fine. Many modern astrologers soften this to: do not start anything new during a void moon, but feel free to finish, rest, or wait.

We do not show a live void-of-course indicator on this page, because identifying it requires computing the Moon's ongoing aspects to every classical planet — outside the scope of the synodic-cycle calculation that powers everything above. If void-of-course timing matters to your practice, consult a dedicated horary calendar or ephemeris.