Free online moon phase calendar. Check moon phase for any date — new moon, first quarter, full moon, last quarter. Shows moon age and illumination percentage. Essential for astronomers and photographers. | No sign-up · Pure client-side computation
Zero Dependencies · Works OfflineSelect a date to see the moon phase, age, and illumination
Select a date to see the moon phase, age, and illumination
Uses the Conway astronomical algorithm based on the 29.53-day synodic month. Sufficient for daily use (error <1 day). For astronomical-grade precision (eclipse prediction), use professional software.
Moon phases affect tides and nighttime brightness. Many cultures link moon phases to agriculture (planting/harvesting), fishing, and traditional festivals. Full moon nights are great for photography; new moon nights for stargazing.
Use the date picker to navigate months and years, or click Previous/Next to browse day by day. The algorithm supports any date.