Moon Phase Software

Tools & method

Moon calculators for exact dates and locations

Start with one precise local instant to calculate phase angle, illumination, lunar age, waxing or waning direction, and the previous and next principal phases. Distinct tools add orbital geometry, observer-specific sky position, and global lunar eclipse searches. Inputs are supported from 1900 through 2100.

Calculate an exact instant

Use an IANA name such as UTC, Europe/London, America/New_York, or Asia/Tokyo.

Brass lunar instrument and Moon observation monitor in a dark coastal observatory

Live UTC reading

Current default instant

Calculated phaseWaning Gibbouswaning
73.47%illuminated
Phase angle
242.01°
Lunar age
20.45 days
Calculated instant

This reading follows the current UTC minute. Use the controls above to resolve any supported past or future instant.