Frequently Asked Questions

Our calculations are powered by Astronomy Engine, a high-precision library validated against the US Naval Observatory's NOVAS C 3.1 and NASA/JPL Horizons data. Times are accurate to within approximately 1 arcminute for any location on Earth. The calculations include full atmospheric refraction correction (the Moon appears slightly above the horizon when it is geometrically just below it) and topocentric parallax correction for your exact position on Earth's surface.

The Moon orbits Earth in the same direction Earth rotates. Each day, the Moon moves about 13.2° eastward in its orbit, so Earth must rotate an extra 13.2° (about 50 minutes) for the Moon to appear in the same position in the sky. The actual delay varies from 25 to 75 minutes depending on your latitude and the Moon's orbital geometry.

Yes! The Moon is above the horizon for roughly 12 hours each day, just like the Sun. Depending on its phase, much of that time can be during daylight. For example, a First Quarter Moon rises around noon and sets around midnight. The Moon is often visible during the day — it's just harder to spot against the bright sky.

Because the Moon's daily delay is about 50 minutes, occasionally a moonrise or moonset falls just before midnight one day and just after midnight the next, meaning there's technically no moonrise or moonset on the intervening calendar day. Near the poles, the Moon can stay above or below the horizon for extended periods.

A Supermoon occurs when a Full Moon coincides with the Moon's perigee (closest approach to Earth at about 225,623 miles). This makes the Moon appear up to 14% larger and 30% brighter than when it's at apogee (farthest point). The term was coined by astrologer Richard Nolle in 1979; astronomers prefer "perigee-syzygy."

Latitude significantly affects moon times. At the equator, the daily delay is consistently close to 50 minutes. At higher latitudes, the Moon's path makes a shallower angle with the horizon, which can compress the delay (as little as 25 minutes during the Harvest Moon at northern latitudes) or stretch it (up to 75+ minutes). Near the poles, the Moon may not rise or set for days at a time.

The Moon doesn't orbit in sync with the Sun. Its position in the sky changes throughout its monthly cycle, and for about half the month, the Moon is above the horizon during at least part of the daytime. A crescent Moon near sunset or a gibbous Moon in the afternoon sky are common daytime sightings. The Moon is bright enough to be visible against the blue sky — we just tend not to notice it.

A lunar eclipse occurs when Earth passes between the Sun and Moon, casting Earth's shadow on the Moon. This can only happen during a Full Moon. Total lunar eclipses give the Moon a reddish color (called a "Blood Moon") because Earth's atmosphere bends red light into the shadow. Lunar eclipses don't happen every Full Moon because the Moon's orbit is tilted 5.1° relative to Earth's orbit around the Sun.

While folklore links the Full Moon to sleep disruption and behavioral changes, scientific evidence is mixed. Some studies have found slightly reduced deep sleep around the Full Moon, possibly related to increased ambient light. However, large-scale studies have not confirmed consistent effects on emergency room visits, crime rates, or psychological episodes. The Moon does affect some animal behaviors, particularly in marine species whose activities are linked to tidal cycles.

Both whendoesthemoonset.com and whendoesthemoonrise.com run the same codebase. The site detects which domain you're visiting and adjusts the primary focus — moonset times on the moonset domain, moonrise times on the moonrise domain. All moon data (rise, set, phase, arc) is shown on both sites.