Technical and media time

Moon Phase and Lunar Event Calendar

Estimate lunar age, illumination, phase, and nearby lunar events.

PrivacyRuns in your browser
OutputCalendar builder
CostFree to use
Calendar builder

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Results update after calculation and include a visual timeline, calendar, or dashboard.

Purpose and scope

What this calendar builds

Estimate lunar age, illumination, phase, and nearby lunar events.

The Moon Phase and Lunar Event Calendar generates dated occurrences from Calendar date, Lunar cycles to preview, Display UTC offset, and Calendar detail; Review Calendar detail at cycle and month boundaries.

InterfaceCalendar builder
CategoryTechnical and media time
Date reviewCycles and boundaries
OutputDated occurrences

Instructions

How to use this calculator

Enter the target date, number of lunar cycles to preview, display offset, and desired level of detail.

  1. Enter Calendar date and Lunar cycles to preview as the Moon Phase and Lunar Event Calendar anchor.
  2. Enter Display UTC offset and Calendar detail for the recurrence cutoff.
  3. Generate the Moon Phase and Lunar Event Calendar output and review its first Calendar detail cycle.
  4. Check the final Moon Phase and Lunar Event Calendar occurrence with Calendar date and Lunar cycles to preview.
  5. Check the Moon Phase and Lunar Event Calendar reference with the Calendar detail definition or convention.

Calculation

Method used

Lunar age is estimated from a known new-moon epoch and the average synodic month. Illumination follows the phase angle.

Lunar age = elapsed days since a known new moon modulo 29.530588 days. Illumination = (1 − cos(phase angle)) ÷ 2.

The Moon Phase and Lunar Event Calendar advances Calendar date, Lunar cycles to preview, and Display UTC offset between occurrences; review Calendar detail before applying any exclusion.

Calculation method last reviewed: June 21, 2026.

Visual audit

Reading the generated calendar

The Moon Phase and Lunar Event Calendar calendar generates entries from Calendar date, Lunar cycles to preview, Display UTC offset, and Calendar detail. Review Calendar detail across full cycles, weekends, and month boundaries.

Worked scenario

Example calculation

Example: A lunar age near half of 29.53 days corresponds to a full moon and illumination near 100 percent.

Check the Moon Phase and Lunar Event Calendar example anchor with Calendar date and Lunar cycles to preview, then review the Calendar detail boundary direction.

Interpretation

Reviewing the generated schedule

Use the phase name and nearby event calendar for general planning, not precision observation.

Review Calendar detail on each Moon Phase and Lunar Event Calendar date; check that Calendar detail with the recurrence basis and cutoff.

Practical use

Recommended workflow

Use an astronomical ephemeris when precise observation, navigation, or photography timing matters.

Boundaries

Important edge cases and limitations

Orbital variation, exact conjunction time, location-dependent moonrise, eclipses, libration, and atmospheric visibility are excluded.

Revise Calendar detail through the Moon Phase and Lunar Event Calendar inputs; generate the full cutoff set instead of editing one date.

Input audit

Checklist for this calculation

  • Review the Moon Phase and Lunar Event Calendar anchor in Calendar date and Lunar cycles to preview.
  • Check the first occurrence with Calendar detail.
  • Review Calendar detail at weekends and month ends.
  • Generate the Moon Phase and Lunar Event Calendar again after a recurrence revise.
  • Check the Moon Phase and Lunar Event Calendar reference with the Calendar detail date and use case.

Verification

References

Reference and calculation method reviewed: June 21, 2026.

Questions

Frequently asked questions

Why can an official full-moon time differ?

The synodic month is an average. Precise lunar motion varies and requires a full astronomical model.

When should NASA: Moon phases be checked for the

Check NASA: Moon phases with Calendar detail whenever the Moon Phase and Lunar Event Calendar cutoff affects a decision. Retain its version or access date beside Calendar date.

Should a Calendar detail update refresh the

A revised Calendar detail makes the older Moon Phase and Lunar Event Calendar stale unless Calendar date uses the same working data. Generate a new Moon Phase and Lunar Event Calendar output for the revised Calendar detail case.

How should Calendar date be recorded for the

Calendar date anchors the Moon Phase and Lunar Event Calendar sequence, while Calendar detail controls its recurrence or review horizon. Check the anchor before comparing individual dates.