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Full moon
Full moon — The whole disc lit. Middle of the cycle (day ~14–15).
About this phase
At full moon the Earth lies roughly between the Sun and Moon, so we see the entire lit face. It rises around sunset and sets around sunrise, staying up all night. This is the phase most tied to folklore — and the one most studied for any effect on sleep.
Each phase is a stage in the roughly 29.5-day cycle as the sunlit part of the Moon that faces us grows or shrinks. Left and right lit sides here are as seen from the Northern Hemisphere.
All eight phases
| Phase | Appearance | Cycle position |
|---|---|---|
| New moon | Effectively invisible | Start of the cycle (day 0) |
| Waxing crescent | A thin sliver on the right, growing | First few days after new moon |
| First quarter | Right half lit (Northern Hemisphere) | About a week in (day ~7) |
| Waxing gibbous | More than half, still growing | Second week (days ~8–14) |
| Full moon | The whole disc lit | Middle of the cycle (day ~14–15) |
| Waning gibbous | More than half, now shrinking | Third week (days ~16–21) |
| Last quarter | Left half lit (Northern Hemisphere) | About three weeks in (day ~22) |
| Waning crescent | A thin sliver on the left, fading | Final days before new moon |
This page explains the phase, not the calendar. For the exact next date of this phase where you are, check an astronomical almanac.
Source: Standard astronomy references on lunar phases. · checked 2026-09-04
Frequently asked questions
What does the full moon look like?
The whole disc lit. At full moon the Earth lies roughly between the Sun and Moon, so we see the entire lit face. It rises around sunset and sets around sunrise, staying up all night. This is the phase most tied to folklore — and the one most studied for any effect on sleep.
When in the cycle is the full moon?
Middle of the cycle (day ~14–15). The full cycle of phases repeats about every 29.5 days.
Track your sleep through the cycle
Log your nights with TempoLife and see for yourself whether the Moon makes any difference.