In answer to this it may be said that Lord Kṛṣṇa appeared in the dynasty which is in the hierarchy of the moon; therefore, although the moon was incomplete on that night, because of the Lord's appearance in the dynasty wherein the moon is himself the original person, the moon was in an overjoyous condition, so by the grace of Kṛṣṇa he could appear just like a full moon.
In an astronomical treatise by the name Khamaṇikya, the constellations at the time of the appearance of Lord Kṛṣṇa are very nicely described. It is confirmed that the child born at that auspicious moment was the Supreme Brahman, or the Absolute Truth.
Vasudeva saw that wonderful child born as a baby with four hands, holding conchshell, club, disc and lotus flower, decorated with the mark of Śrīvatsa, wearing the jeweled necklace of kaustubha stone, dressed in yellow silk, appearing dazzling like a bright blackish cloud, wearing a helmet bedecked with the vaidūrya stone, valuable bracelets, earrings and similar other ornaments all over His body, and beautified by an abundance of hair on His head.