MoonPhase []
gives moon phase fraction of illumination for the current date.
MoonPhase [datespec]
gives moon phase fraction of illumination for the specified date.
MoonPhase [property]
gives the property of the moon phase for the current date.
MoonPhase [datespec,property]
gives the property of the moon phase for the specified date.
MoonPhase
MoonPhase []
gives moon phase fraction of illumination for the current date.
MoonPhase [datespec]
gives moon phase fraction of illumination for the specified date.
MoonPhase [property]
gives the property of the moon phase for the current date.
MoonPhase [datespec,property]
gives the property of the moon phase for the specified date.
Details and Options
- The phase of the Moon, also known as the lunar phase, describes the illumination of the lunar surface by the Sun as seen from Earth.
- MoonPhase [] makes use of $TimeZone to determine your time zone.
- datespec can be a DateObject expression, a TimeObject expression or a date string.
- datespec is assumed to be in $TimeZone , unless it is a DateObject or TimeObject expression with an explicit TimeZone option value.
- If datespec is a list of dates, then the results will be given as EventSeries or TimeSeries objects.
- datespec can be specified as {start,end,increment} for compatibility with DateRange specifications.
- MoonPhase ["Fraction"] is equivalent to MoonPhase [].
- MoonPhase can accept the following values for property:
-
"Fraction" or "IlluminationFraction" fraction of illumination, from 0 to 1"SignedFraction" or "SignedIlluminationFraction" signed fraction of illumination, from -1 to 1"PhaseAngle" lunation angle, from 0 to 2π"PhaseAngleFraction" fraction of lunation angle, from 0 to 1"Name" name of the moon phase"Icon" icon representing the moon phase
- MoonPhase […,Method "method"] specifies how moon phases are defined. Fraction of illumination, as observed from the center of the Earth, is used by default.
- Possible settings for the Method option include:
-
"Illumination" phase defined by fraction of illumination of the Moon"EclipticLongitude" phase defined by Moon‐Sun ecliptic longitude difference
Examples
open all close allBasic Examples (4)
Find the Moon's current fraction of illumination:
Find the Moon's fraction of illumination on a specified date:
Find the name of the Moon's current phase:
Generate an icon of the Moon's current phase:
Scope (7)
Dates can be specified as a DateObject :
Dates can be specified as a date string:
Results for a range of dates:
Generalizations & Extensions (1)
IconData can accept the signed fraction of the moon phase as its second argument:
Options (1)
Method (1)
By default, MoonPhase uses illumination of the Moon by the Sun to compute properties:
Alternatively, use a method based on the ecliptic longitude difference between Moon and Sun:
Properties & Relations (1)
By default, the date is specified by the current date:
Possible Issues (1)
The names of moon phases are based on the illumination fraction value. On a given day, the name of the moon phase may change, depending on what time it is. For example, a full moon does not last a full day, so even if a full moon occurs on that day, you may have to change the time in order to get the phase you might expect:
Neat Examples (1)
Create a moon calendar:
See Also
MoonPosition SunPosition AstroPosition TideData LunarEclipse SolarEclipse PlanetaryMoonData
Function Repository: MoonPhaseDate
Related Guides
Text
Wolfram Research (2014), MoonPhase, Wolfram Language function, https://reference.wolfram.com/language/ref/MoonPhase.html (updated 2025).
CMS
Wolfram Language. 2014. "MoonPhase." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 2025. https://reference.wolfram.com/language/ref/MoonPhase.html.
APA
Wolfram Language. (2014). MoonPhase. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/MoonPhase.html
BibTeX
@misc{reference.wolfram_2025_moonphase, author="Wolfram Research", title="{MoonPhase}", year="2025", howpublished="\url{https://reference.wolfram.com/language/ref/MoonPhase.html}", note=[Accessed: 04-December-2025]}
BibLaTeX
@online{reference.wolfram_2025_moonphase, organization={Wolfram Research}, title={MoonPhase}, year={2025}, url={https://reference.wolfram.com/language/ref/MoonPhase.html}, note=[Accessed: 04-December-2025]}