There are several index dates to determine the beginning of the Kali-Yuga. According to the  Surya Siddhanta, Kali Yuga began at midnight (00:00) on 18 February 3102 BCE in the proleptic 
    Julian calendar, or 23 January 3102 BCE in the proleptic Gregorian calendar. This date is also considered by many Hindus to be the day that Krishna left Earth to return to his abode. 
    Tradition says that the planets Saturn, Mars, Venus, Jupiter, Mercury and the Sun and the Moon were all situated near the nakshatra Revati.  (According to Surya Siddhanta and Jyotisa 
    sastra) With Inner Sky Electrum Synoptical Astrology Software (for Windows 7 and Windows Vista) I can display the whole celestial schema (inside: tropical zodiac, in the middle: 
    sidereal vedic lunar mansions (Nakshatra), outermost zone: true stellar constellations along the Ecliptic.