JIT is primarily applied in slang and street language to refer to the youth, particularly in the Southern parts of the U.S. It is observed in hip-hop culture, the internet forums, and everyday speech. People call it nostalgically and refer to their own younger self or people use it to make a comment on how old a person is or how they behave. It has informal meaning and cannot be used in a professional or academic setting. Know more about Jit Urban Dictionary