lodestarA birth chart and a transit chart answer different time questions. One points to the moment of birth. The other brings in the sky on a date you choose. Astrologers sometimes place the two together to compare them.
A birth chart begins at one moment
A birth chart maps the Sun, Moon, and planets for the recorded birth time and place. In astrology, those positions form a starting map. The chart does not change when the calendar moves on.
Transits add another date
A transit shows where planets are on a chosen date and compares those positions with a birth chart. This is a method astrologers use to discuss changing themes over time. The positions can be calculated, but the meaning assigned to a comparison is an interpretation.
A comparison is not a promise
If you read a transit description, ask what part connects with your actual experience. It cannot guarantee that an event will happen. Also check whether a service really calculates transits before treating a daily message as a personal transit reading.
A few common questions
Does my birth chart turn into a transit chart each day?
No. The birth chart keeps its birth positions; transits add positions for another date to compare with them.
Sources & further reading
Astrology sources describe their own traditions and methods; they do not establish predictive accuracy. The writing exercises are original Lodestar editorial material.