Tehnički detalji
How the Moon Phase Calculator Works
What the Tool Does
The Moon Phase Calculator displays the current moon phase, illumination percentage, and phase name (New Moon, Waxing Crescent, First Quarter, Waxing Gibbous, Full Moon, Waning Gibbous, Last Quarter, Waning Crescent). It also provides a monthly calendar view showing the phase for each day, so you can quickly find upcoming full moons, new moons, and quarter phases without consulting an almanac.
Common Use Cases
Photographers and outdoor enthusiasts check moon phases to plan night shoots, stargazing sessions, or camping trips when they want either bright moonlight or dark skies. Gardeners who follow lunar planting calendars use it to time sowing and harvesting. Fishermen consult moon phases for tidal and feeding activity predictions. The tool is also used by astrology practitioners who track lunar cycles for rituals, intention setting, and energy work.
Data Formats, Types, or Variants
Moon phases are calculated using the synodic month (approximately 29.53 days from new moon to new moon). The eight named phases divide this cycle into roughly equal segments. Illumination is expressed as a percentage from 0% (new moon) to 100% (full moon). The calculation uses a simplified astronomical algorithm based on the moon's ecliptic longitude relative to the sun, which is accurate to within a few hours for most practical purposes.
Common Pitfalls and Edge Cases
The simplified algorithm used here does not account for the moon's elliptical orbit, libration, or parallax, so illumination percentages may differ slightly from observatory data. Moon rise and set times are not included because they depend on the observer's geographic latitude and longitude. The phase names use equal divisions of the synodic month, while astronomical definitions may place quarter phases at exact 90°/270° elongation, which can differ by up to a day.
When to Use This Tool vs Code
Use this tool for a quick visual check of tonight's moon or to scan the month ahead. For applications requiring precise moonrise/moonset times, eclipse predictions, or location-specific data, use an astronomy library like SunCalc (JavaScript), Skyfield (Python), or the USNO API that computes positions from full ephemeris tables with sub-minute accuracy.