Look up the moon phase, illumination, lunar age, and the next full and new moon for any date — computed locally with the Conway approximation, no API calls.
Computed forward from the chosen date by sampling phase progression at 1-hour resolution. Times shown in your local timezone.
Uses the synodic month length of 29.530588 days and a known new moon reference of 2000-01-06 18:14 UTC. The illumination fraction is computed as (1 − cos(2π·age/29.530588)) / 2. This gives accuracy within a few hours over centuries — great for almanacs, fiction, photography planning, or moonrise-aware UI copy. Not for navigation or eclipse prediction.