About a year in each sign
Jupiter usually spends about a year in each sidereal sign, long enough to affect a whole chapter of life. A published Jupiter transit for a sun sign cannot tell you which house it occupies from your lagna and from your Moon, whether it aspects a natal graha, or whether a Jupiter dasha is already running. Jupiter through the ninth house is a different year from Jupiter through the sixth. The janam kundli is needed to place the transit.
What a Jupiter transit tends to touch
Jupiter signifies study, teachers, children, faith, law, long travel, and judgement. A transit tends to expand the matters of the house it occupies and the houses it aspects. Expansion can bring support, but it can also enlarge a problem or encourage promises that the rest of the chart cannot sustain. Jupiter is a natural benefic, yet its transit still needs the lagna, natal Jupiter, Saturn, and dasha for context.
A year of Jupiter is not a Jupiter dasha
A Jupiter mahadasha lasts sixteen years, while Jupiter usually transits one sign for about a year. These are separate forms of timing. A supportive transit during a difficult dasha may provide help within a harder period. A prominent Jupiter transit during a Jupiter dasha may bring major growth, but can also increase advice, expectation, or excess. The natal Jupiter shows the lasting condition; Guru gochara shows the current emphasis.
How to ask about a Jupiter transit here
A reading compares Guru gochara with natal Jupiter, the houses it occupies and aspects, Saturn's position, and the active dasha. Bring your date, exact time, and place of birth, then ask about study, a child, a teacher, law, travel, faith, or an opportunity developing this year.

