Your chart never changes. The sky crosses it.

If your natal chart is a map, transits are its clock. The map tells you where; transits tell you when. At the moment you were born the planets stood at particular degrees, and that arrangement is fixed for life. But the sky did not stop: the Sun, Moon and planets are still moving through the zodiac today.

When a planet in today's sky forms a specific angle to a point in your natal chart, that is a transit. If today's Saturn arrives exactly opposite your natal Sun, Saturn is said to be transiting in opposition to your Sun. The chart has not changed — the sky crossing it has.

That distinction carries the whole timing side of astrology. A natal chart is read once and stays true for years; transits change from week to week. The answer to "why does this stretch feel the way it does" is not in the natal chart but in the sky currently moving across it.

Deciding when a transit begins is not arbitrary, but it does need a rule. A planet counts as being in contact for a while before it reaches the exact degree of the aspect, and for a while after it passes. That tolerance is called the orb, and it is measured in degrees.

The orb limits Baby Astro uses are these: conjunction 8°, opposition 8°, trine 7°, square 6°, sextile 4°. Each widens by 1.5° when the Sun or Moon is involved, because the luminaries are traditionally granted a larger sphere of influence. An aspect outside those limits does not appear in the app at all — there is no "weak square" category; it is either inside the limit or it is not.

The orb also sets the strength. The closer a transit sits to exact, the more clearly it reads, fading to nothing as it approaches the limit. Transits in a relationship reading are held tighter still — a 3° orb there, showing only the four closest contacts, because filling a synastry screen with fifteen faint transits is clutter rather than information.

Two things set the weight of a transit: which aspect it is, and which planet is making it. The aspect type gives the tone — a conjunction intensifies, trines and sextiles flow, squares and oppositions create friction. The planet gives the duration.

The Moon is fastest: its transits last a few hours, which is why it is used to read the emotional weather of a day. The Sun, Mercury and Venus stay for a few days. Mars for weeks. Jupiter and Saturn for months — and because of retrograde motion they can cross the same point three times, which is how one theme comes back around three times within a year.

The best-known example is the Saturn return. Saturn takes roughly 29.5 years to circle the Sun, so at about twenty-nine it comes back to the degree it held when you were born. Jupiter's lap is about twelve years. These are astronomical facts rather than claims — what they mean is the tradition's interpretation, when they happen is arithmetic.

A transit does not produce events. A Saturn square will not cost you your job; a Venus trine will not deliver someone to your door. Tradition reads transits as periods in which certain kinds of experience become more visible — rather like weather. Rain does not mean you are staying in; it means you might think about an umbrella.

Baby Astro presents transits in that language. The app does not tell you what will happen. It tells you which contacts are currently open, what the tradition reserves them for, and when they close. If you ask it for a guaranteed future, a medical diagnosis or a timing of death, it declines — a considered boundary rather than a missing feature.

The useful application is this: when a stretch is harder than you expected, transits give that difficulty a name and an end date. That does not change what is happening, but it does give you a frame to think inside — and for most people, that is precisely where astrology earns its keep.