moon-cycle/.github/wiki/api/variables/SYNODIC_MONTH.md

moon-cycle v2.0.0

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moon-cycle / SYNODIC_MONTH

Variable: SYNODIC_MONTH

const SYNODIC_MONTH: 29.53058821398858 = 29.53058821398858

Defined in: types.ts:51

Length of one synodic month in days.

IAU mean value at J2000.0. Used by cycleMonth to divide the elapsed time into a fractional position within the current lunar cycle.

Example

import { SYNODIC_MONTH } from 'moon-cycle';
// Days old: how far into the current cycle
const now = new Date();
const elapsed = (now.getTime() - MONTH_ANCHOR.getTime()) / 86400000;
const age = ((elapsed % SYNODIC_MONTH) + SYNODIC_MONTH) % SYNODIC_MONTH;