User blog comment:FairyRaven/Fairy Tail Chapter 424: Avatar, Review and Commentary/@comment-24.90.189.198-20150316160334/@comment-76.161.172.226-20150316175704

The gap between the GMG and the Sun Village arc should be no more than a couple months.

Most likely it was a few weeks, to a couple months from the GMG to the Sun Village arc, and Natsu's training time was somewhere over ten months, rounded up to a year for convenience sake. Future Rogue's "Frosch dies in about a year", gives a lot more slip time than people give it credit for anyways. A year and two months is still "about a year".