About Moon Huddle
A quiet place to check what the Moon is doing tonight, and on any night you care about.
What it is
Moon Huddle has five free tools: a moon phase calendar, moonrise and moonset times, full moon dates and names, the moon phase for any date and a dark-night stargazing planner. They are made for people who plan a walk under the full moon, a night of photography or a trip to a dark-sky park, and for anyone curious what the Moon looked like on a day that matters to them.
How it works
Every number is calculated in your browser from published astronomical methods: the positions of the Sun and Moon follow Jean Meeus's Astronomical Algorithms (2nd edition, 1998), and rise, set and twilight follow the definitions of the US Naval Observatory. Nothing is looked up online. The built-in city list and your browser's time zone database give local times, including daylight-saving changes. We checked the results against the Naval Observatory's 2026 tables for London, Sydney and Tromsø: rise, set and twilight times agree to within about a minute, and phase times to within a minute.
What it is not
Times are for an ideal flat horizon at sea level. Mountains, buildings, your height and unusual weather change what you actually see by a few minutes. For navigation, legal or safety-critical timing, use an official almanac.
Sources
US Naval Observatory: phases of the Moon and percent illuminated and rise, set and twilight definitions. Traditional full moon names: The Old Farmer's Almanac. Jean Meeus, Astronomical Algorithms, 2nd ed., Willmann-Bell, 1998 (Open Library record).