esbat provides functions for lunar phase calculations.
The algorithms are as published in Calendrical Calculations: The Ultimate Edition by Edward M. Reingold and Nachum Dershowitz, used with permission. The book notes:
... the algorithms are centered around the present date, for which they are accurate to within about 2 minutes. Their accuracy decreases for the far-distant past or future.
This crate uses a non-commercial license, a Creative Commons Attribution-NonCommercial 4.0 International License, at the request of the authors of Calendrical Calculations. Please contact the author of this crate at firstname.lastname@example.org for any licensing questions.
Principal phase iterator by day.
Principal phase iterator.
The eight principal and intermediate phases of the Moon.
The four principal phases of the Moon.
Calculates the lunar phase for a given date.
Returns an iterator of principal phases and the days they fall on.
Calculates the lunar phase for a given moment.
Returns an iterator of principal phases and their moments.