As stated in the Bhagavad-gītā (3.9), every action of life produces another reaction, which is binding upon us, and only those who are acting on behalf of Yajña (Viṣṇu) are not bound by reactions. Our actions are judged by the higher authorities, the agents of the Lord, and thus we are awarded bodies according to our activities. The law of nature is so subtle that every part of our body is influenced by the respective stars, and a living being obtains his working body to fulfill his terms of imprisonment by the manipulation of such astronomical influence. A man's destiny is therefore ascertained by the birthtimeconstellation of stars, and a factual horoscope is made by a learned astrologer. It is a great science, and misuse of a science does not make it useless. Mahārāja Parīkṣit or even the Personality of Godhead appear in certain constellations of good stars, and thus the influence is exerted upon the body thus born at an auspicious moment. The most auspicious constellation of stars takes place during the appearance of the Lord in this material world, and it is specifically called jayantī, a word not to be abused for any other purposes. Mahārāja Parīkṣit was not only a great kṣatriya emperor, but also a great devotee of the Lord. Thus he cannot take his birth at any inauspicious moment. As a proper place and time is selected to receive a respectable personage, so also to receive such a personality as Mahārāja Parīkṣit, who was especially cared for by the Supreme Lord, a suitable moment is chosen when all good stars assembled together to exert their influence upon the King.
(Srimad Bhagavatam-----1:12:12-----purport).

Śrī Śukadeva Gosvāmī clearly answered: When a potter's wheel is moving and small ants located on that big wheel are moving with it, one can see that their motion is different from that of the wheel because they appear sometimes on one part of the wheel and sometimes on another. Similarly, the signs andconstellations, with Sumeru and Dhruvaloka on their right, move with the wheel of time, and the antlike sun and other planets move with them. The sun and planets, however, are seen in different signs and constellations at different times. This indicates that their motion is different from that of the zodiac and the wheel of time itself.
(Srimad Bhagavatam-----5:22:2-----translation).

The sun-god, who is Nārāyaṇa, or Viṣṇu, the soul of all the worlds, is situated in outer space between the upper and lower portions of the universe. Passing through twelve months on the wheel of time, the sun comes in touch with twelve different signs of the zodiac and assumes twelve different names according to those signs. The aggregate of those twelve months is called a saṁvatsara, or an entire year. According to lunar calculations, two fortnights—one of the waxing moon and the other of the waning—form one month. That same period is one day and night for the planet Pitṛloka. According to stellar calculations, a month equals two and one quarter constellations. When the sun travels for two months, a season passes, and therefore the seasonal changes are considered parts of the body of the year.
(Srimad Bhagavatam-----5:22:5-----translation).

When the moon is waxing, the illuminating portions of it increase daily, thus creating day for the demigods and night for the pitās. When the moon is waning, however, it causes night for the demigods and day for the pitās. In this way the moon passes through each constellation of stars in thirty muhūrtas (an entire day). The moon is the source of nectarean coolness that influences the growth of food grains, and therefore the moon-god is considered the life of all living entities. He is consequently called Jīva, the chief living being within the universe.
(Srimad Bhagavatam-----5:22:9-----translation).

Thereafter, at the auspicious time for the appearance of the Lord, the entire universe was surcharged with all the qualities of goodness, beauty and peace. The constellation Rohiṇī appeared, as did stars like Aśvinī. The sun, the moon and the other stars and planets were very peaceful. All directions appeared extremely pleasing, and the beautiful stars twinkled in the cloudless sky. Decorated with towns, villages, mines and pasturing grounds, the earth seemed all-auspicious. The rivers flowed with clear water, and the lakes and vast reservoirs, full of lilies and lotuses, were extraordinarily beautiful. In the trees and green plants, full of flowers and leaves, pleasing to the eyes, birds like cuckoos and swarms of bees began chanting with sweet voices for the sake of the demigods. A pure breeze began to blow, pleasing the sense of touch and bearing the aroma of flowers, and when the brāhmaṇas engaging in ritualistic ceremonies ignited their fires according to Vedic principles, the fires burned steadily, undisturbed by the breeze. Thus when the birthless Lord Viṣṇu, the Supreme Personality of Godhead, was about to appear, the saints and brāhmaṇas, who had always been disturbed by demons like Kaṁsa and his men, felt peace within the core of their hearts, and kettledrums simultaneously vibrated from the upper planetary system.
(Srimad Bhagavatam-----10:3:1-5-----translation).

When the time was mature for the appearance of the Lord, the constellations became very auspicious. The astrological influence of the constellation known as Rohiṇī was also predominant because this constellation is considered very auspicious. Rohiṇī is under the direct supervision of Brahmā, who is born of Viṣṇu, and it appears at the birth of Lord Viṣṇu, who in fact is birthless. According to the astrological conclusion, besides the proper situation of the stars, there are auspicious and inauspicious moments due to the different situations of the different planetary systems. At the time of Kṛṣṇa's birth, the planetary systems were automatically adjusted so that everything became auspicious.
(Srimad Bhagavatam-----10:3:1-5-----purport).

A learned brāhmaṇa named Upendra Miśra, who resided in the district of Śrīhaṭṭa, was the father of Jagannātha Miśra, who came to Navadvīpa to study under the direction of Nīlāmbara Cakravartī and then settled there after marrying Nīlāmbara Cakravartī’s daughter, Śacīdevī. Śrī Śacīdevī gave birth to eight children, all daughters, who died one after another immediately after birth. After her ninth pregnancy she gave birth to a son, who was named Viśvarūpa. Then, in 1407 Śaka Era (A.D. 1486), in the full-moon evening of the month of Phālguna, with the constellation of Siṁha (Leo) on the horizon, Lord Caitanya Mahāprabhu appeared as the son of Śrī Śacīdevī and Jagannātha Miśra. After hearing of the birth of Caitanya Mahāprabhu, learned scholars and brāhmaṇas, bringing many gifts, came to see the newborn baby. Nīlāmbara Cakravartī, who was a great astrologer, immediately prepared a horoscope, and by astrological calculation he saw that the child was a great personality. This chapter describes the symptoms of this great personality.
(Sri Caitanya Caritamrta-----13-----summary).

When Kṛṣṇa used to play on His flute, the vibration appeared just like the roaring of clouds in the sky during the constellation of Svātī. According to Vedic astronomical calculation, if there is rain during the constellation of the Svātī star, any rain falling on the sea will produce pearls, and rain falling on a serpent will produce jewels. Similarly, when Kṛṣṇa's flute roared like a thundercloud under the Svātī constellation, the resulting perspiration on Śrīdāmā's body appeared to be just like pearls.
(Nectar of Devotion).

In the Bhagavad-gītā the Lord says that His appearance, birth and activities are all transcendental and that one who understands them factually becomes immediately eligible to be transferred to the spiritual world. The Lord's appearance or birth is not like that of an ordinary man, who is forced to accept a material body according to his past deeds. The Lord's appearance is explained in the Second Chapter: He appears out of His own sweet pleasure. When the time was mature for the appearance of the Lord, the constellations became very auspicious. The astrological influence of the star known as Rohiṇī was predominant. This star is considered to be very auspicious and is under the direct supervision of Brahmā. According to the astrological conclusion, besides the proper situation of the stars, there are auspicious and inauspicious moments due to the different situations of the different planetary systems. At the time of Kṛṣṇa's birth, the planetary systems were automatically adjusted so that everything became auspicious.
(Krsna Book).