An adaption of the "Dark Phoenix" Saga which ran in the Uncanny X-Men comics #129 - 138 from January until October 1980.
Although the original Dark Phoenix saga is set in 1980, the song Dazzler performs at the night club is "Sweet Child O' Mine" by Guns N' Roses which was released in 1988, cementing yet again that the series is set in a modern day setting.