How we calculate
UmbraLux calculates every date and time on this page itself, with the astronomy library astronomy-engine – the same calculation the UmbraLux app uses for its charts. As usual in astrology, positions are measured in the tropical zodiac: the signs start at the vernal equinox and span 30° each.
New moon, first quarter, full moon and last quarter are the moments when the Moon stands 0°, 90°, 180° or 270° east of the Sun, measured by the apparent positions of Sun and Moon – as the astronomical almanacs define them. The Moon changes sign when it crosses into the next zodiac sign, about every two and a half days.
An automated test compares our times for 2026 and 2027 with published values: all 99 moon phases lie within one minute of NASA JPL Horizons, and it checks them against the US Naval Observatory's tables too. The 24 moon sign changes it checks (one a month) lie within one minute of JPL Horizons.
Moon phase and moon sign
A moon calendar shows two things: the moon phase, how much of the Moon is lit (from new moon through the first quarter to full moon and back through the last quarter), and the moon sign, the zodiac sign the Moon is in. The Moon runs through its phases in about 29.5 days and through all twelve signs in about 27.3 days, so the full moon falls in a different sign every month.
The moon calendar tradition
In German-speaking countries the moon calendar is also a tradition for house, garden and body care, made popular above all by the German book "Vom richtigen Zeitpunkt" ("The right moment") by Johanna Paungger and Thomas Poppe. By this tradition every moon sign and phase has its favourable activities. We describe the tradition and calculate the dates for it.
Questions about the moon calendar
What is the moon phase today?
Today, Tuesday, October 13, 2026, the Moon is in Scorpio and waxing (9% lit). The next full moon is on Monday, October 26, 2026, at 04:12 UTC.
Which sign is the Moon in today?
The Moon is in Scorpio, until tomorrow 00:59 UTC, then into Sagittarius.
When are the next full moon and new moon?
Full moon: Monday, October 26, 2026, at 04:12 UTC, in Taurus. New moon: Monday, November 9, 2026, at 07:02 UTC, in Scorpio.
When does the moon calendar say to cut your hair?
By the moon calendar tradition on days when the Moon is in Leo or Virgo: with a waxing Moon so the hair grows back faster, with a waning Moon so the cut lasts longer. In the next six weeks these are November 1, November 2, November 3, November 4 and November 5.
How often does the Moon change sign?
About every two and a half days: 160 times in 2026, 160 times in 2027. The time of every change is in the calendar.
Which time zone does the moon calendar 2027 use?
All times are in UTC, which has no summer time. For London add one hour from the last Sunday of March to the last Sunday of October.
When are the eclipses of 2027?
February 6, 2027: annular solar eclipse; February 20, 2027: penumbral lunar eclipse; July 18, 2027: penumbral lunar eclipse; August 2, 2027: total solar eclipse; August 17, 2027: penumbral lunar eclipse.
By year
More calendars
Matching calculators
- Birth moon phaseNew moon, full moon or in between: the phase, the light and the age of the Moon at your birth.
- Moon signThe sign the Moon stood in when you were born.
- Birth chartChart wheel with planets, Placidus houses, Ascendant, MC and aspects.
- Sun signThe sign of the Sun at your birth, on the day it changes sign too.
Sources
- astronomy-engine (Don Cross) : the calculation library the UmbraLux app uses too
- NASA JPL Horizons : reference values of our test
- U.S. Naval Observatory, Astronomical Applications : reference values of our test