How this works
It is one loop, not a pile of readings
OrbHeaven calculates the stretches ahead for your birth chart and gives you the dates, answers a question against those dates, comes back on the day the stretch peaks to ask how it actually went, and keeps your answer. Four steps, and the fourth feeds the first. Everything in the menu is a way into that loop, and every page says whether what it shows was calculated, drawn by chance, or written by you.
One loop, on a real date
Today
You ask something
Not a horoscope: a question about a thing you are actually deciding.
9 Nov
New Moon in Scorpio
A day that is known in advance. It comes back and asks how it went.
After
It remembers what you said
Your answer goes on the record, and the next one starts from it.
- 1
How does it know what is coming?
It works out what is actually coming
Your chart is calculated from your birth details, to the minute, and then run forwards. The Timeline gives you real dates: when a stretch starts building, the day it peaks, when it eases. None of that is written by Vesper or anyone else. It is arithmetic on where the planets are, and you can check it against any ephemeris.
Timeline, When, My Chart, Today
- 2
What happens when I ask it something?
You bring it something real
Ask a question and you get an answer grounded in that chart, the sky right now, and whatever you have told Vesper before. Every question is also offered one small thing to do about it in the meantime, chosen by the transit that is actually pressing rather than picked out of a hat.
Ask, and the ritual card that comes with each question
- 3
What makes this different from a horoscope?
It comes back and asks how it went
This is the part almost nothing else does. When you ask a question, the app picks a date to return, usually the day the transit peaks or eases, and on that day it asks you what actually happened. One tap. That answer is the whole point: it turns a reading into a record with an outcome attached.
Today, when a check-in is due, or a day you chose on When has passed
- 4
What do I get for staying?
It remembers, and reads the record back
What you said gets kept and used. Over a few months Patterns can tell you which kinds of stretch you find harder than you expect, what you keep asking about, and whether the daily notices land. That is the thing that gets better the longer you stay, and it cannot be faked on day one.
Patterns, and every answer afterwards
Then it starts again, with more behind it than last time. The fourth step is why the third one matters, and the third is why this is worth paying for rather than reading a horoscope. Run the first step now on the free birth chart; each dated stretch is a transit.
The calculation
How the calculation is done
1
Birth details
Date, time and a place from a list.
2
Civil time resolved
The clock time, by the rules for that place and date.
3
Universal time
One moment, the same everywhere.
4
Astronomical positions
Where each body was, from the engine.
5
Angles and houses
Ascendant, Midheaven and cusps, from the place.
6
Aspects and orbs
Angles between points, within a stated orb.
7
The displayed result
To the minute of arc, settings named.
8
Interpretation
What it means: a reading, not a measurement.
What goes in
A birth date, a birth time and a birthplace chosen from a list. The place sets the coordinates and the time zone; the clock time is read by the time-zone rules in force there on that date, from the international time-zone database, and becomes one universal time. Where the same time happened twice because the clocks went back, the chart asks which one you mean; a time the clocks skipped, or a date that never happened there, is refused rather than guessed. Time-zone records are strongest from 1970 onward; earlier ones can be less certain.
Where the planets were
Every position comes from astronomy-engine 2.1.19, an open-source astronomy library bundled with the app. It works out where each body appeared from the centre of the Earth at that moment: the apparent longitude, light travel time and aberration included, on the true ecliptic and equinox of that date. Put plainly: the sky as seen from Earth, on the zodiac that starts at the March equinox, the tropical zodiac. The bodies are the Sun, Moon, Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto, with the lunar nodes as the mean node; no asteroids, Chiron, Lilith or fixed stars. Retrograde is read from a planet’s own motion at that instant.
The framework
Houses are Placidus, and there is no setting to change that. Placidus is undefined at latitudes near the poles; there the chart uses whole-sign houses and says so on its face. The Ascendant and Midheaven come from the moment and the place together. Six aspects are kept: conjunction, sextile, square, trine, opposition and quincunx. The angle between two points is measured; the orb, how far from exact still counts, is a convention, not a measurement. The orb allowed is shown with every aspect, and there is no setting to change the orbs either. Applying or separating comes from the two bodies’ motion.
Without a birth time
Tick the box and the chart is worked out across every real moment of that civil date. Each body becomes a range, shown in whole degrees; where a body changed sign that day, both signs are shown and no degree. Aspects are marked certain when they held all day and possible when they depend on the hour. The Ascendant, Midheaven and houses need a time and are left out; no rising sign is guessed. In the Timeline, a date that depends on the birth time becomes a range of dates (without a birth time).
What is shown, and how to check it
Positions are shown to the degree and minute of arc, orbs to a tenth of a degree, and the cast moment as local time and universal time to the minute. The arithmetic runs at full precision; only the display is rounded. Under every chart are the engine and its version, the zodiac, the node convention and the house system. To check one, take the universal time printed under it and look the planets up in any other ephemeris; modern ephemerides agree on the planets to well within the minute shown.
Where calculation ends
Positions, angles, houses, aspects and the dates in the Timeline are calculated; nothing in them is written by anyone. What any of it means is interpretation: an astrological reading of a measured sky. Vesper reads the calculated chart and dates and writes against them; Vesper does not calculate the positions and cannot change them. A rune or a card is real chance, drawn with a secure shuffle, and says so. What you wrote stays yours, and every page says which kind it is.
See how a birth chart is built, step by step — a walkthrough of the four layers, with an example chart drawn by the same engine.
Questions about the calculation
- How does OrbHeaven calculate a birth chart?
- In the eight steps above: the birth time becomes universal time by the rules for that place and date, positions come from astronomy-engine, angles and Placidus houses from the place, and aspects within stated orbs.
- What astronomical data does OrbHeaven use?
- astronomy-engine 2.1.19, an open-source astronomy library bundled with the app, which computes geocentric apparent positions for the true ecliptic and equinox of date. Every chart names the engine and version.
- Which zodiac and house system does OrbHeaven use, and can I change them?
- The tropical zodiac and Placidus houses, and no, neither can be changed. Where Placidus is undefined near the poles, whole-sign houses are used and the chart says so.
- How are time zones and daylight saving handled?
- By the rules in force at the birthplace on the birth date, from the international time-zone database, daylight saving included. A clock time that happened twice is asked about; a time the clocks skipped is refused. Records are strongest from 1970 onward.
- What happens if I don’t know my birth time?
- The chart is worked out across the whole birth date: every position is a range in whole degrees, both signs where a body changed sign, aspects certain or possible, and no Ascendant, Midheaven or houses. Nothing is guessed.
- Why can two astrology calculators give different results?
- Rarely because of the planets. The differences are conventions: the zodiac, the house system, the orbs, the time-zone rules applied to the birth date, rounding, what is done without a birth time, and which bodies and points are included. A different answer is not necessarily a wrong one; the comparisons show other apps’ conventions. Why astrology calculators give different results shows how large each difference can be.
- How can I check the numbers?
- Take the universal time printed under the chart and look the positions up in any other ephemeris, remembering that OrbHeaven uses the tropical zodiac, the mean node and Placidus houses; the angles need the birthplace’s coordinates too. Today’s sky shows the positions right now.
The map
What is in here, and what each part is for
Three groups, by how a thing is decided. Today, Ask and the Timeline are the loop; the rest is there when a question makes you want it. What is free says which need an account.
Your record
What you asked, and what you said happened.
Ask, Intentions, Dreams, Your story, Your days, Letters, Patterns
Calculated
Worked out from your birth details. Nothing here is guessed.
Timeline, Numerology, Your animals, When, People, My Chart
Drawn
Chosen by chance, honestly, and it says so.
Tarot, Runes, I Ching
What does the first week look like?
Day one you get your dates and one question answered. Over the next few days the brief ends with something to watch for, and the evening asks whether it showed up. Somewhere in the first week a check-in comes back and asks how an earlier question turned out. By then Patterns has something to say that it could not have said on day one, because it is made of your answers rather than your birthday.
About a minute. Birth time optional, and no account until after you have seen it.