Give some stream of consciousness and then the answer. The third season of the animated television series Rick and Morty originally aired in the United States on Cartoon Network's late night programming block, Adult Swim. It premiered with "The Rickshank Rickdemption," which aired unannounced on April 1, 2017 and was replayed every half hour from 8pm to 12am ET, as part of Adult Swim's annual April Fools' prank. The episode was also simulcast as a looping live stream on Adult Swim's site. The remaining episodes began airing four months later and concluded on October 1, 2017 with "The Rickchurian Mortydate". This season aired a total of ten episodes, despite co-creator Justin Roiland stating that they were "supposed to do 14 this season".

Based on this passage, when is the new rick and morty episode airing?
To answer the question, consider the following: It premiered with "The Rickshank Rickdemption," which aired unannounced on April 1, 2017 and was replayed every half hour from 8pm to 12am ET, as part of Adult Swim's annual April Fools' prank.
Therefore, the answer is April 1 , 2017.