Chapter Nine Text 1
duryodhana uvaaca muni-shaardula bhagavaan balabhadro naaga-kanyaabhir gopibhih kadaa kaalindi-kule vijahaara.
duryodhana uvaaca-Duryodhana said; muni-shaardula-O tiger of sages; bhagavaan-Lord; balabhadrah-Balaraama; naaga-snake; kanyaabhih-with the girls; gopibhih-with the gopis; kadaa-when?; kaalindi-kule'on the Yamunaa's shore; vijahaara-enjoyed pastimes.
Duryodhana said: O tiger of sages, when did Lord Balaraama enjoy the raasa dance on the Yamunaa's shore with gopis that had been snake-girls in their previous birth?
April 14th marks the auspicious remembrance day of Lord Balarama's springtime rasa dance with His cowherd girlfriends. It is also the day of Sri Krishna Vasanta Rasa, the Lord's springtime rasa lila pastime. Sri Krishna Vasanta rasa takes place on Vaisakha purnima, which is also the time Balarama performs His springtime rasa dance with the gopis.
"In order to keep the gopis in Vrndavana satisfied, Lord Balarama stayed there continually for two months, namely the months of Caitra and Vaisakha. For those two months he kept himself among the gopis and he passed every night with them in the forest of Vrndavana in order to satisfy their desire for conjugal love. Thus Balarama also enjoyed the rasa dance with the gopis during those two months." (Krsna Book II p.78)
Balarama, who has the same original form of Krsna, is Himself a cowherd boy in Vrndavana, and He also considers Himself to belong to the ksatriya race in Dvaraka. Thus His color and dress are different, and He is called a pastime form of Krsna.
(from The Sampradaya Sun)