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DateDelta
See which of the 8 lunar phases the Moon is in on any given date, past or future.
The Moon's orbit isn't perfectly circular or constant-speed, so the true time between new moons varies by several hours around the 29.53-day average used here — this calculator is accurate to within roughly a day, which is precise enough for general reference but not exact astronomical prediction.
0% illumination is a New Moon (fully dark), 100% is a Full Moon (fully lit) — the percentage describes how much of the visible lunar disk appears lit from Earth's perspective on that date.
Duration between two times of day, in hours and minutes.
OpenHours worked from clock-in, clock-out, and break time.
OpenWeekly total hours and overtime from daily entries.
OpenAnnual cost of your daily commute.
OpenMoon phase
First Quarter
48% illuminated
What you entered
Days since the reference new moon (Jan 6, 2000)
(date − reference) ÷ 1 day, mod synodic month= 7.2071 days into the cycleMatch against the 8 standard moon phases
7.2071 ÷ 29.5306 × 8= First QuarterApproximate illumination
(1 − cos(2π × cycle position)) ÷ 2= 48.1332%Result
Moon phase: First Quarter
On 2026-07-22, the Moon is in its First Quarter phase, roughly 48% illuminated — this is an approximation based on the average 29.53-day lunar cycle, accurate to within about a day.