purvah parardho 'pakranto
yat-that which; ardham-half; ayusah-of the duration of life; tasya-his; parardham-a parardha; abhidhiyate-is called; purvah-the former; parardhah-half of the duration of life; apakrantah-having passed; hi-certainly; aparah-the latter; adya-in this millennium; pravartate-shall begin.