Blue Moon Calendar
Date+ MoonPhase()+ illumination= daily disc
KnownMonth + yearFindDaily phaseSampleLocal noonSourceAstronomy EngineOutputMoon gridProofElongation
CalculationTime
Blue Moon Calendar
A printable lunar planning sheet for monthly and seasonal blue moon definitions, engine-backed full moon dates, local UTC offsets, prep dates and source caveats beside the CalculationTime clockface.
Inputs, result, proof and time.
Use the instrument above, then check the calculation record, assumptions and related tools below.
Printable blue moon calendar
Blue moon watch sheet
Sydney, Australia - 2027- UTC offset
- +10h
- Definition
- Both
- Full moons
- 12
- Blue moons
- 1
Seasonal blue moon
Thu, 20 May 2027
Third full moon in a four-full-moon autumn season.Prep dateThu, 13 May 20277 days before
Calendar monthMay 2027Local offset basis
SeasonAutumnSouth hemisphere lens
DefinitionSeasonalTraditional naming varies
22 JanJanuary 202721 FebFebruary 202722 MarMarch 202721 AprApril 202720 MayMay 202719 JuneJune 202719 JulyJuly 202717 AugAugust 202716 SeptSeptember 202715 OctOctober 202714 NovNovember 202714 DecDecember 2027
Planner Notes
Check a current observatory almanac before publishing exact full moon times. Use this sheet for reminders, content planning and observation prep.
Assumptions
Full moon instants are generated with Astronomy Engine SearchMoonQuarter and quarter 2. Local dates use the entered UTC offset only after the UTC search.
Limits
This is a printable planning worksheet, not an official ephemeris. Exact lunar phase times, daylight-saving changes and local visibility need current almanac confirmation.
Method
The worksheet finds unusual full moon patterns and keeps the definition visible
The calculator generates full moons with Astronomy Engine, applies the selected UTC offset, groups local full moon dates by month and by engine season boundaries, then flags either the second full moon in a calendar month or the third full moon in a season that contains four full moons.
Two definitions
Modern usage often calls the second full moon in a calendar month a blue moon. Older almanac usage can mean the third full moon in a four-full-moon season.
Print path
The print button opens browser print. The print stylesheet keeps blue moon rows, full moon list, local offset, planner notes, assumptions and source limits.
Limits
This is a planning calendar, not an observatory almanac, tide table, astrology claim, ceremonial authority, navigation aid or official lunar phase source.
Source Notes
Blue moon labels depend on definition and exact phase times
CalculationTime uses Astronomy Engine phase and season searches for printable planning worksheets. Exact full moon instants can shift local calendar dates near midnight, so still use official almanacs or observatory data before publication, education material, travel or public event scheduling.