A birth chart never changes — it is the photograph of the sky at your first breath. But the sky itself keeps moving, and gochar (transit) is the study of how today's planetary positions pass over the sensitive points of that photograph. A transit does not rewrite your chart; it rings the bells your chart already contains.
This is why the same Saturn transit is a harvest for one person and a pruning for another. The event in the sky is common to everyone; what it touches in your chart — and which dasha you are running when it does — is entirely personal.
The slow planets set the seasons
In practice, three movers matter most. Saturn spends about two and a half years in a sign — its transits are life's slow examinations, including the famous Sade Sati around your Moon. Jupiter spends about a year per sign, opening doors of growth, learning and family blessings wherever he walks. Rahu and Ketu take about eighteen months per sign, turning appetite and detachment onto new arenas. The fast planets — Moon, Mercury, Venus, Sun, Mars — colour days and weeks rather than years.
Transits are read from the Moon as much as the Lagna
Classical gochar is counted from the natal Moon sign — Saturn's third, seventh and tenth from the Moon are traditionally productive, Jupiter's fifth, seventh and ninth generous, and so on. A careful reading checks both the Lagna and the Moon, because life happens in the mind as much as in the world.
Dashas decide how loudly a transit speaks
The rule Dr. Nidhi returns to: dashas propose, transits dispose. A magnificent Jupiter transit during an unrelated dasha may pass as a pleasant month; the same transit while Jupiter's own period runs can crown a decade. This layering — promise (chart), permission (dasha), trigger (transit) — is why timing questions deserve a full reading rather than a headline.
Using transit seasons well
Transits are for preparing, not fearing. A demanding Saturn season is the right time to simplify, complete and strengthen foundations; an expansive Jupiter season the right time to launch, learn and marry effort to opportunity. Knowing the season lets you choose the work that the season rewards.