Horoscopes that talk about "this week" or "the months ahead" are almost always talking about transits, even when they never use the word. A transit is a dated event: a planet moving through today's sky reaches a particular angle to a point in your birth chart. Because it has a date, it can go on a calendar, and a calendar makes the rhythm of a few months visible at a glance.
This guide explains what a transit is, how aspects and orbs decide whether one exists, why a useful transit calendar leaves the Moon out, what retrograde motion does to the dates, and how to read the colored grid produced by the free Dating & Personal Growth Calendar. Throughout, it keeps two things separate: the planetary positions are astronomy and can be checked, while the meanings attached to them are astrological tradition, not measured science.
TL;DR: A transit is an angle, called an aspect, between a planet's current position and a fixed point in your birth chart. The Toolz Dating & Personal Growth Calendar scans the Sun, Mercury, Venus, Mars, Jupiter and Saturn against your natal planets (plus your ascendant and midheaven if you give a birth time and place) for the next 30, 60, 90 or 180 days. Each transit is listed once, on the day it is closest to exact. Trines and sextiles are marked supportive, squares and oppositions frictional. The Moon is excluded because it would put contacts on every day. It runs client-side, free, no signup, and the readings are traditional interpretation, not prediction.
What is a transit in astrology?
A transit is an aspect between a planet as it is positioned in the sky on a given day and a fixed position in your birth chart. Your birth chart records where the Sun, Moon and planets were at the moment you were born. Those natal positions never move. The planets keep moving, and as they do they form angles to the natal positions.
For example, if your natal Venus sits at 15 degrees Taurus and Jupiter today is at 15 degrees Virgo, Jupiter is 120 degrees from your Venus. Astrologers call that transiting Jupiter trine natal Venus. It builds as Jupiter approaches the exact angle, peaks on the day the angle is closest, and fades as Jupiter moves on.
The natal chart describes a starting point; transits describe timing. That is why transits underpin most forward-looking astrology, from monthly forecasts to the popular idea of a "Saturn return".
How do aspects and orbs work?
An aspect is one of a small set of angles between two points on the zodiac circle, and an orb is how far from the exact angle an aspect still counts. The five major aspects come from dividing the 360-degree circle by 1, 2, 3, 4 and 6.
The Toolz calendar uses these five aspects and these orbs, taken from its source code:
| Aspect | Exact angle | Orb | Tone in the calendar | Traditional reading |
|---|---|---|---|---|
| Conjunction | 0° | 8° | Neutral | Fused: the two act as one, for better or worse |
| Sextile | 60° | 5° | Supportive | Opportunity that has to be taken up |
| Square | 90° | 7° | Frictional | Friction: a source of drive and of frustration |
| Trine | 120° | 7° | Supportive | Easy support, with no friction and no push |
| Opposition | 180° | 8° | Frictional | Tension that needs balancing rather than resolving |
When the Sun or the Moon is one of the two points, the orb is widened by 2 degrees, a common convention on the reasoning that the Sun and Moon dominate a chart. So transiting Mars square natal Moon counts within 9 degrees, while transiting Mars square natal Venus counts within 7.
Orbs are not standardized. Different astrologers use different values, and two calculators disagreeing about whether a transit exists is almost always an orb disagreement rather than an arithmetic error. The table above is what this calendar uses.
Worked example: when is a trine in orb?
Natal Venus at 15° Taurus is 45 degrees of ecliptic longitude (Aries covers 0 to 30, Taurus 30 to 60). A trine is 120 degrees away in either direction, so the exact trine points are 165° (15° Virgo) and 285° (15° Capricorn).
With a 7-degree orb, transiting Jupiter is trine natal Venus anywhere from 158° to 172°, that is 8° to 22° Virgo. Jupiter takes about 12 years to go around the zodiac, so it averages about one degree every 12 days. Crossing a 14-degree window at that pace takes several months, longer if it turns retrograde inside it.
That is the practical problem with slow transits. Listing every day the trine is "in orb" would fill half a year of calendar with the same entry. The next section shows how the calendar deals with it.
How does the calendar choose which days to mark?
The calendar marks each transit on one day only: the day its orb is smallest. It checks the planets' positions once a day at noon UTC across your chosen window, and for each pairing of a moving planet with a natal point, it keeps an aspect only on a day where the orb is tighter than the day before and no looser than the day after. Ties go to the earlier day.
So a Saturn square that stays within orb for weeks produces one dated entry, not twenty. It also means:
- A transit that peaked just before the window opens is not listed, even if it is still in orb on day one.
- A transit that is still tightening when the window closes is not listed either. It peaks outside the window.
- Dates are calendar days in UTC, and the peak is resolved to the day, not the hour. If you live far from UTC, an event near midnight may fall on the adjacent local date.
The window starts at midnight UTC today and runs for 30, 60, 90 or 180 days. The default is 60.
Which planets are scanned, and why is the Moon left out?
The calendar scans six moving bodies: the Sun, Mercury, Venus, Mars, Jupiter and Saturn. They are checked against these natal points: Sun, Moon, Mercury, Venus, Mars, Jupiter and Saturn, plus the ascendant and midheaven when you enter a birth time and place.
The Moon is left out as a moving body because it is too fast to produce a useful calendar. The Moon completes a circuit of the zodiac in about 27.3 days, the sidereal month given in NASA's Moon fact sheet. In one circuit it passes through all eight exact major aspect angles to any fixed point (0°, 60°, 90°, 120°, 180°, 240°, 270° and 300°). Against nine natal points, that is 8 × 9 = 72 exact lunar aspects every 27.3 days, or about 2.6 a day. A calendar that included them would mark every single day, which means it would highlight nothing.
Your natal Moon is still a target. Transiting Venus trine your natal Moon is in the calendar; the transiting Moon is not.
Uranus, Neptune and Pluto are not scanned either. They move so slowly that a transit from one of them lasts a year or more and rarely peaks inside a short window.
Here is how the scanned bodies compare in speed, which determines how often each contributes an event:
| Moving body | Time to circle the zodiac | What that means for the calendar |
|---|---|---|
| Sun | 1 year | 8 exact major aspects to each natal point per year |
| Mercury | About 1 year, with retrograde loops | Frequent, sometimes repeated |
| Venus | About 1 year, with retrograde loops every 19 months or so | Frequent, sometimes repeated |
| Mars | About 2 years | A few per season |
| Jupiter | About 12 years | Rare, significant when they appear |
| Saturn | About 29.5 years | Rare, the slowest events listed |
In a 30-day window, most entries come from the Sun, Mercury and Venus. Longer windows add the occasional Jupiter or Saturn peak.
How do you read the colored grid?
Each day in the window is a cell showing the day of the month and, if anything peaks that day, the number of transits. The color gives the day's tone:
| Color | Tone | Meaning |
|---|---|---|
| Green | Supportive | At least one trine or sextile, and no squares or oppositions |
| Red | Frictional | At least one square or opposition, and no trines or sextiles |
| Amber | Mixed | Both supportive and frictional contacts peak that day |
| Gray | Quiet | Nothing supportive or frictional peaks |
One detail is easy to miss. Conjunctions are treated as neutral, so a day where only a conjunction peaks is colored gray like a quiet day, but it shows a count. A gray cell with a number is not empty. Check the list for it, because conjunctions, including a Saturn return, are some of the most discussed transits.
Mixed days are common and are not a failure of the method. Several things happening at once is the ordinary case.
Under the grid, "Dates worth knowing" lists each day with events, such as "Jupiter trine your natal Venus", with a supportive, frictional or neutral label and a one-line traditional reading of the aspect. The heading above the grid tells you how many transits peak in the whole window.
Do "supportive" and "frictional" mean good and bad?
No. The labels describe the character astrology traditionally gives an aspect, not its value. Trines and sextiles are read as ease and opportunity. Squares and oppositions are read as pressure, effort and change, and astrological tradition consistently treats those as the contacts associated with growth. A stretch of nothing but easy contacts is not described in astrology as a productive time.
It is also worth being direct about evidence. The planetary positions in this calendar are measurable astronomy. The claim that those positions shape events or moods is not supported by controlled studies; a well-known double-blind test of astrologers' chart interpretations, published by Shawn Carlson in Nature in 1985, found they performed no better than chance. The calendar is a way to engage with a long cultural tradition, and the page's disclaimer says the same: the readings are offered for interest and are not advice about relationships, health, money or any other decision.
What does retrograde motion do to the dates?
Retrograde motion can make the same transit appear two or three times. A planet appears to move backward through the zodiac for a while because Earth, on a faster inner orbit, overtakes it, or it overtakes Earth in the case of Mercury and Venus. The planet has not changed direction; the view from Earth has.
If a planet reaches an exact aspect, turns retrograde, moves back over the same degree, then turns direct and crosses it again, the transit is exact three times. Astrologers call this a triple pass. Because the calendar computes each day's real position instead of assuming steady forward motion, each pass is a separate dated entry.
For example, over a six-month window you might see Saturn square natal Sun listed in one month, then again two or three months later as Saturn backs over the degree, with the third pass falling outside the window. Seeing the same pairing more than once is expected, not a duplicate.
What is a Saturn return, and will the calendar show it?
A Saturn return is transiting Saturn arriving back at the position it held when you were born. Saturn's orbital period is about 29.46 years according to NASA's Saturn fact sheet, so returns happen around age 29 to 30, again around 58 to 59, and around 88. Astrology reads the first one as a period of taking stock and growing up.
If a Saturn return peaks inside your window, it appears as Saturn conjunction your natal Saturn. Because conjunctions are neutral, that day is colored gray with a count. With retrograde passes, a Saturn return often shows as up to three entries over most of a year, so use the 6-month window and check again later.
How do you build your calendar?
- Open the personal transit calendar and enter your birth date. A date alone is enough for transits to your planets.
- Add a birth time and birth city if you have them. That brings in your ascendant and midheaven, which change sign every couple of hours and so need both.
- Choose a window: next 30, 60, 90 days, or 6 months. Use short windows for the near term and 6 months to catch slow Jupiter or Saturn contacts.
- Click Build my calendar, scan the grid for the shape of the period, then read the dated list for specifics.
If your birth time was recorded in a time zone different from the one you live in now, the time zone converter guide explains offsets and daylight saving. If you want to count the days between today and a listed date, the date difference guide covers that arithmetic.
How does the calendar relate to other astrology tools?
The calendar is one of several chart tools, and each answers a different question.
| Question | Tool |
|---|---|
| Where was everything when I was born? | Birth chart calculator |
| What are my Sun, Moon and rising signs? | Sun, Moon and rising calculator |
| How do two charts interact? | Synastry chart calculator |
| Which days ahead carry contacts to my chart? | Dating & Personal Growth Calendar |
The birth chart shows the natal positions the calendar measures against, so it is a good place to start if the list names a point you do not recognize. The whole set is on the astrology tools hub.
Choosing dates on purpose, such as for a wedding or a launch, is its own branch of the tradition called electional astrology, and it weighs far more factors than a single transit. A transit calendar narrows the field; it does not settle a date.
Is my birth data private?
Yes. The chart and the whole transit scan run in your browser. Your birth date, time, place and name are not uploaded or stored, and the calendar keeps working offline once the page has loaded. A daily usage limit applies, and what is recorded for it is only whether a birth time was unknown and whether a place was given, never the details themselves.
