Horary astrology as the name suggests is based on Hora or the planetary hour being operational. It is a way of chart reading done when either the birth chart is not available or the question asked can not be answered from the birth chart. For such cases horary chart comes to help. It also help in cases where the person is beginner or wants to aid his knowledge of birth chart reading with horary chart’s help.
Now coming to your question about horary astrology being accurate, it depends on few factors,
The person who asked the question should be free from worries and that question should be his priority at that moment

The astrologer who answers should have his/her basics strong

If the above conditions are fulfilled then the horary chart will be really helpful because the moment someone ask a question is pre determined. No one goes to ask a question to an astrologer till the time that horary chart doesn’t reflect the question. Horary chart helps to know about the question in the seeker’s mind and offer to help solutions to it, help to time events, etc.

PS: if someone wants to test the astrologer’s knowledge or want to just make fun then i must tell you that horary chart reflects it as well. It again shows that astrology is purely divine and no human being is above it.
A horary chart and an astrological chart are both types of astrological charts that are used to study the positions of celestial bodies and their influence on individuals or events. However, there are some key differences between the two:
Purpose: A horary chart is used to answer specific questions or address specific concerns, while an astrological chart is used to gain a more general understanding of a person’s character, strengths, weaknesses, and life path.
Timing: A horary chart is cast for the moment a question is asked or an event occurs, while an astrological chart is cast for the moment of a person’s birth.
Interpretation: Horary charts are often used to make predictions or provide guidance in specific areas of life, such as relationships, career, or finances. Astrological charts, on the other hand, are used to gain a deeper understanding of a person’s character and life path, and to identify patterns and themes that may influence their experiences.
Scope: Horary charts are focused on a specific question or event, while astrological charts provide a more comprehensive overview of a person’s life.
It’s important to keep in mind that astrology is not a science and that the interpretation of horary and astrological charts is subjective and can vary depending on the practitioner’s approach and training. Some people find astrology to be a valuable tool for self-discovery and personal growth.