The half hour series premiere debuted on December 17, 1989 with "Simpsons Roasting on an Open Fire" a Christmas special. The next episode "Bart the Genius" was the first to feature the series' full title sequence, including the chalkboard gag and couch gag. Matt Groening developed the lengthy sequence in order to cut down on the animation necessary for each episode, but devised the two gags as compensation for the repeated material each week. Groening, who had not paid much attention to television since his own childhood, was unaware that title sequences of such length were uncommon by that time. As the finished episodes became longer, the production team were reluctant to cut the stories in order to allow for the long title sequence, so shorter versions of it were developed.

Answer this question: when was the first episode of simpsons aired? Let's think fast. Stream of consciousness:
To answer the above question, the relevant sentence is: The half hour series premiere debuted on December 17, 1989 with "Simpsons Roasting on an Open Fire" a Christmas special. So the final answer is December 17 , 1989.