Lunar Age Calculator
Lunar Age
-- days
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Note: This is an astronomical approximation. Local observations may vary slightly.
The Synodic Month
A full lunar cycle (Synodic Month) is approximately 29.53 days. The age is the number of days elapsed since the last New Moon.
$$ \text{Age} = (\text{Date} - \text{Reference New Moon}) \pmod{29.53059} $$