User blog comment:IamJakuhoRaikoben/Chapter 245: The Unbranded Man, Review./@comment-3987368-20110730184547/@comment-3987368-20110730193642

Six months to the beginning of the Edolas arc. So then maybe a year before the fighting festival arc or something to that extent.

Also, eating fire never gave him the power of the fire he ate, right? It just made him regain his strength I think. He never could use Totomaru's stink flame again or Bora's prominence fire right? So how would eating Laxus' lighting give him the lightning abilities by just eating, whether it was voluntarily given or not?

I also think that whatever Hiro Mashima's shortcomings as a storyteller (let's not pretend, every does mangaka has 'em), he is, if nothing else, consistent. Natsu eating the lightning and not feeling the negative effects right away (as he felt with Totomaru's stink flame) would be one hell of a blunder, one I doubt he's capable of making at this point in his career.