Planets, signs, and houses do different jobs
Planets represent functions or drives: expression, attachment, communication, motivation, limits, and more. Signs describe the style through which those functions operate. Houses connect the symbolism to areas of life.
Aspects describe angular relationships between planets. They are often read as patterns of ease, tension, reinforcement, or adjustment.
Birth time anchors the chart
The rising sign and house structure change through the day, sometimes quickly. An accurate birth time allows those parts of the chart to be calculated with greater confidence.
The Moon can also change signs on some birth dates. Even when it does not, its exact position shifts over the course of the day.
If your birth time is unknown
Say so rather than guessing. A date-based reading can still discuss many planetary sign placements and broad aspects, but it should not present the rising sign or houses as certain.
A birth certificate, hospital record, baby book, or a family member may help. Rounded family memories such as 'around breakfast' are not the same as a documented time.
Accuracy is not the same as certainty
Even a mathematically precise chart still requires interpretation. Astrology is a symbolic practice, not a medical diagnosis or a guarantee of personality, compatibility, or events.