First published in 1990, this French-language paperback presents a systematic treatment of astrological timing. Authored by Françoise Schneider‑Gauquelin, the work explores methods for resolving the hour of birth and other temporal questions within astrology, offering practical calculations and interpretive guidance. Over 270 pages, readers find detailed explanations of astronomical data, chart construction, and the application of astrological principles to everyday life. The book serves both as a reference for seasoned astrologers and as an instructional guide for those seeking a deeper technical understanding of horoscopic timing.