User blog comment:FairyRaven/Fairy Tail Chapter 336: In Order to Live Today to the Fullest, Review and Commentary/@comment-77.195.192.216-20130622091133/@comment-15267891-20130622125611

an arc about the Stellar Spirit World is possible. 1 day is equal to 3 months in the human world. they don't have to stay in the spirit world longer than 1 day. (example of a 1 day arc is Tenrou Island Arc which lasted 40+ chapters i think)