How we make our 2027 calendars
Every date and time in the 2027 collection is computed from the real sky by Natal Junction's own engine, then converted to the clock of each of five time zone editions. Every Moon phase and eclipse is checked against NASA's published tables; sign changes and stations are checked against a second, independent calculation. No date is copied from another calendar.
Last checked 23 October 2026
How the dates are computed
Two ephemerides run side by side. One is a high-precision numerical ephemeris built on NASA JPL's DE431 planetary data. The other is astronomy-engine, the open-source astronomy library behind this site's free birth chart and Kundali tools. Each printed time comes from one of them and is checked against the other. The Moon phases and eclipses are also checked against NASA Goddard's published tables (Fred Espenak). Any difference over two minutes is fixed or explained before a file ships.
| What we print | Checked against | Result |
|---|---|---|
| Moon phases of 2027 (new, quarter and full) | NASA Goddard Moon phase table (Espenak) | All 49 within 1 minute; 44 print NASA's exact minute |
| The five eclipses: date, type and time of greatest eclipse | NASA Goddard solar and lunar eclipse tables | Every date and type matches; times within 4 seconds |
| Equinoxes and solstices | Espenak's solstice and equinox table | All four within 1 minute |
| Turns retrograde and direct, Mercury to Saturn | A second, independent ephemeris | Every date and degree agrees |
| Void-of-course Moon (Lunar Planner) | A second, independent ephemeris | All 174 starts within 30 seconds |
| Sunrise and sunset (Lunar Planner) | An independent calculation | Within 0.6 minutes in every edition |
| Time zones and daylight saving | The legal clock rules of each zone | All eight clock changes of 2027 match |
| US and UK public holidays | U.S. Office of Personnel Management and GOV.UK | Copied from the official lists |
Western astrology here uses the tropical zodiac and geocentric positions. Shadow dates follow the usual rule: the pre-shadow begins when a planet first reaches the degree where it will later turn direct, and the post-shadow ends when it returns to the degree where it turned retrograde. The Moon's sign changes come from the same ephemeris run and agree with the second engine to within 10 seconds; no published table lists them line by line, so that is the one check made against our own second engine alone.
Time zones
A Moon phase happens at one instant for the whole Earth, so the date on the wall depends on where you live. In 2027, 10 of the 13 New Moons fall on a different date in New York than in Sydney. So every product comes in five editions, each calculated for its own clock: US Eastern, US Pacific, UK, India (IST) and Sydney. Daylight saving is applied on the right day for each zone, and every time is rounded to the nearest minute after it is converted, never before.
Live in US Central or Mountain time? The Pacific edition carries your date on 48 of the 49 Moon phases of 2027, with clock times one or two hours earlier than yours.
How the Moon is drawn
Only the four phase days draw an exact shape: an empty New Moon, a half-lit first and last quarter and a solid full Moon. Every other day sits inside a band, so it never reads as half, full or empty: crescents are drawn 10 to 40% lit and gibbous Moons 60 to 90% lit, moving in even daily steps between the phases. Very small discs use 20 to 40% and 60 to 80%, so the shadow beside a full Moon stays visible in print.
The Northern Hemisphere editions draw the Moon lit on the right as it grows. The Sydney edition of the Moon Calendar and the Lunar Planner mirrors it, the way the Moon looks from the south.
Images and type
The Moon, the Sun and the planets are NASA photographs. Every page is typeset from the computed data. Every font is embedded in the PDFs and none is a Type 3 font. The smallest type is 8 pt in the Lunar Planner and never under 7 pt in the other products, where 7 pt is kept for short labels such as the event lines of a day cell.
What the astrology notes are
The calendars describe the sky: where the Sun, the Moon and the planets are and when they change. Where a page adds astrology, it says what astrologers traditionally associate with an event and asks a question for your own reflection. It never says what will happen to you or when to act.
Astrology notes in these files are for reflection and entertainment. They are not predictions or professional advice.
Corrections
If a date in any file looks wrong to you, tell us through the contact page. We check it against both ephemerides, and a Moon phase or an eclipse against NASA's tables too. A real error is fixed for every buyer. The wider method behind the site's charts and studies is on the About page.