What Date, Time and Place Each Determine in a Birth Chart
A birth chart records how the sky looked at the moment you were born, seen from one particular point on Earth. Three coordinates go into the calculation, and each one settles a different layer of the chart. The date gives you the signs the planets stood in: the Sun stays in a sign for about a month, the Moon changes sign every two and a half days, Saturn sits in one for roughly two and a half years. The time sharpens the Moon's degree, and its real job is setting the Ascendant and the house cusps. The place turns the sky toward your own horizon; two babies born the same minute in Istanbul and Tallinn have their planets in identical signs, but their houses fall differently.
Which sign a planet occupies and which area of life that planet lands in are two separate calculations. The first needs only a date; the second cannot be built without time and place. Astrology does not announce events in advance here. It reads the arrangement of the sky at birth as a symbolic language.