Another question as well please.
Taken from the description of Eidolons...
"Eidolons are treated as summoned creatures, except that they are not sent back to their home plane until reduced to a number of negative hit points equal to or greater than their Constitution score."
So does that mean that once called, it does not get banished til one of the causes of banishment happens (voluntary, summoner unconscious, sleeping, etc). So technically, if called first thing in the morning, it can stay all day until the summoner goes to sleep for the night unless it is banished for one of the banishment reasons?