Moon Phase Calendar Map
Choose a month to view approximate phase names and illumination at noon UTC using a fixed mean synodic cycle. For precise phase times consult an ephemeris.
By Aryan Khan, Founder & Editor · Updated October 2026
Phase labels and illumination are estimates at noon UTC and can differ from a precise local ephemeris.
How to use Moon Phase Calendar Map
A month of nights, visible at once:
This calendar estimates phase names and illumination at noon UTC using a fixed mean synodic cycle. It is an approximation, not a precise ephemeris or a map of moon visibility.
- 1Pick the month and year.
- 2Read each day's phase and lit percentage.
- 3Use “This month” to jump back to today.
What people use Moon Phase Calendar Map for
1. Planning dark-sky weekends
Star parties and meteor nights want the new-moon weekends. The grid finds them months ahead — then the Moon Illumination Calculator prices the in-between nights.
2. Full-moon events and photography
Moonrise-over-the-city shots, full-moon hikes and night markets all need the full date early. The grid is how organisers stop being surprised by their own event.
3. Religious and cultural calendars
Lunar months begin at the crescent; Ramadan, Passover and lunar new years all anchor to this cycle. The calendar shows the astronomy underneath the observance — visibility of a first crescent depends on age and place, and the grid gives the age.
4. Classroom lunar months
A printed month of Moons on the classroom wall teaches the cycle better than any diagram — students watch the lit side grow, flip and shrink across real dates they lived through.
Worked examples
Each calendar cell shows a phase label and estimated illumination at noon UTC. That instant may not correspond to your local evening.
For precise phase instants or local moonrise, consult a reliable astronomical ephemeris or observatory.
How to read the grid
Each cell carries the same three facts — the month is the pattern they make.
| Cell item | Meaning |
|---|---|
| Phase icon and name | The cycle chapter for that date (evaluated at noon UTC) |
| Lit percent | The disc's lit fraction — your night-brightness budget |
| Quarter and full markers | The month's milestones — roughly one of each per month |
| Dark runs | Stretches under ~25% lit around new moon — the observing gold |
The fixed mean-cycle model is approximate; phase dates and illumination can differ from a precise ephemeris.
How to interpret the result
The most common errors come from using a correct result to answer the wrong geographic question. Keep these points in mind for Moon Phase Calendar Map:
- When comparing day length across a year, remember the curve is your latitude's signature: near-equatorial sites hover at twelve hours while high latitudes swing wildly. Choose expectations by latitude, not by calendar folklore.
- Convert solar times to local clock times deliberately: the sun keeps astronomical time, while governments keep political time, and the gap between them is large in many countries. State both when sharing results.
Limits & appropriate use
Solar arithmetic's limits are small but real: the official zenith encodes average refraction, not today's atmosphere; coordinates are rounded to your input's precision; and terrain is absent unless you add height yourself — a mountain rises the sun late and the formulas won't know. Time adds the political layer: zones and DST are human law, and western edges of big zones (Spain, western China) make solar noon wander hours from clock noon. Every output here therefore carries its convention and both clocks, because an unanchored sunrise time is an argument, not a fact.
Lunar and seasonal outputs carry their own gentle limits: phase from the synodic approximation is hours-precise, which outruns every planning need but not ephemeris science; day length is geometric daylight, not sunshine, and clouds belong to climate's department. Escalation is rare and well-defined — astronomical almanacs and ephemerides for science, terrain-aware apps for mountain photography, and the tz database maintainers whenever a government invents a new DST rule at 48 hours' notice, as they delight in doing.
- Science-grade ephemerides → astronomical almanacs/JPL horizons.
- Mountain sunrise/sunset → terrain-aware horizon adjustments.
- Legal daylight definitions → jurisdictional statutes (they vary!).
Data & methodology
A fixed mean synodic period anchored to 2000-01-06; approximate phase and illumination are evaluated at noon UTC, not from a precise ephemeris.
For source details, licences and model limitations, see Data Sources and Methodology.
Key terms worth knowing
- Synodic month
- The 29.53-day new-moon-to-new-moon cycle behind phases.
- Declination
- The sun's latitude-equivalent angle, ±23.44° across the year.
Editorial guidance: MapBench explains the method and limitations so the tool can be used as a transparent reference, not as a black-box answer. For legal boundaries, safety-critical routing, surveying, engineering, regulated decisions or official statistics, verify the result with the responsible authority or a qualified professional.
Category: Sun & Moon. Results are intended for everyday analysis and planning unless a page explicitly states otherwise.
Method, assumptions & limits
- This tool’s method
- A fixed mean synodic period anchored to 2000-01-06; approximate phase and illumination are evaluated at noon UTC, not from a precise ephemeris.
- Before relying on the answer
- Check the date, location and time zone together. A solar or lunar event is tied to all three, and some events do not occur at high latitudes on a given date.
- What the result cannot establish
- A calculated event assumes the model's horizon and atmospheric conventions. Buildings, terrain and local weather can alter what you observe.
Coverage: Worldwide. Search, basemap and external data requests may use third-party services; browser-based does not mean every operation is offline. Read the source and licence notes, calculation methodology and privacy policy. If a result looks inconsistent, report a correction with the inputs and mode used.
Frequently asked questions
Clear answers about the calculation, accuracy and appropriate use.
How are the phases computed?
From the known synodic period (29.53 days) counted from the new moon of 6 January 2000 — the standard approximation.
Is this an ephemeris-grade table?
Quarter moments can land a few hours off the exact instant — fine for planning a night out, not for astronomy papers.
Are sunrise and solar times exact to what I will see?
Calculated events use astronomical geometry. Terrain, buildings, weather and atmospheric conditions can shift what an observer actually sees.
Does daylight saving change the Sun's position?
No. Daylight saving changes the civil clock label, not solar geometry. Timezone rules affect displayed local time.
Why can polar locations show unusual results?
High latitudes can have days when the Sun does not rise or set, so some solar events legitimately do not occur on a selected date.
Why can the full-moon date differ from my wall calendar?
The model uses a fixed mean cycle at noon UTC, rather than an exact lunar ephemeris. Both model error and time-zone differences can change a date.
Some months have no full moon — really?
February can: with 28 days and a 29.53-day cycle, a February roughly once in two decades holds no full moon (last in 2018). The grid shows the two fulls crowding into January and March instead.
Does the grid work for past centuries?
The year control supports 1950–2100. The mean-cycle approximation is not suitable as a precise historical ephemeris.
Can I see illumination for a whole season?
Chain the months — the pattern repeats every 19 years almost exactly (the Metonic cycle), which is why Easter tables and this calendar are cousins.
Why noon UTC for each date?
A single evaluation instant keeps dates comparable worldwide. Evenings near a phase boundary belong to the neighbouring cell in some timezones — the model says so rather than hiding it.
Southern hemisphere view?
The phases and percents are global; the icons' lit side mirrors below the equator. The calendar's numbers travel; its pictures wear a northern accent.
How do I find the darkest weekend quickly?
Scan for the new-moon cell and take the Friday-to-Sunday around it — then check the Moon Position Map for whether even the crescent is up late.
Related tools and resources
One date deep: the Moon Phase Calculator; percents: the Moon Illumination Calculator; exact fulls: the Next Full Moon Calculator; live position: the Moon Position Map.
More free tools
Sources, methodology & editorial trust
- ✓ Browser-first processing where supported
- ✓ External sources are documented
- ✓ No account required for public tools
- ✓ Review data sources
Calculations are documented with their assumptions, limitations and source context rather than presented as unexplained answers.
Reviewed and maintained by Aryan Khan, Founder & Editor of MapBench.
Part of our sun & moon hub
Moon Phase Calendar Map sits in the sun & moon cluster, alongside 27 other tools that answer neighbouring questions with different methods or datasets.
You may also need
When this answer is only part of the job, these clusters cover the next step.
Read the guide behind this tool
Chasing Golden Hour: A Photographer's Solar Toolkit — Golden hour is an altitude band, not a fixed clock time. How to plan light with solar tools — windows, horizons and moon phase — instead of guessing.