According to the Jyotir-veda, or Vedic astronomy, when the figure of the lion appears both in the zodiac and the time of birth [lagna], this indicates a very high conjunction of planets, an area under the influence of ṣaḍ-varga and aṣṭa-varga, which are all-auspicious moments.
The divisions of the ṣaḍ-varga area are technically called kṣetra, horā, drekkāṇa, navāṁśa, dvādaśāṁśa and triṁśāṁśa. According to Jyotir-vedic astrology, when it is calculated who rules the constellation of six areas, the auspicious moment is calculated. Śrīla Bhaktisiddhānta Sarasvatī Ṭhākura, who was previously also a great astrologer, says that in the book named Bṛhaj-jātaka and other books there are directions for knowing the movements of the stars and planets. One who knows the process of drawing a straight line and thus understands the area of aṣṭa-varga can explain the auspicious constellations. This science is known especially by persons who are called horā-śāstra-vit, or those who know the scripture of the name Horā.
Ref >> Srila Prabhupada Vani.