What is a moon phase calendar?

A moon phase calendar shows the lunar phase for each day in a month view. It is a quick way to see when the new moon, first quarter, full moon, and last quarter fall.

Tool description

This tool displays moon phases on a calendar and adds the illumination percentage to each day. The main phases are color coded, and a legend below the calendar helps you read the view at a glance.

Features

  • Shows moon phases for the visible date range
  • Labels each event with the phase name and illumination percentage
  • Includes a legend for the principal moon phases

How it works

The tool calculates moon phases for the dates in view, converts them into calendar events, and colors each event based on the moon illumination. When you move through the calendar, the visible month range updates and the phases are recalculated.

Notes

  • The calendar is most useful when you want a simple monthly overview instead of a detailed astronomy app.
  • The legend highlights the four main phases so the color coding is easier to read.