It seems like some people are confused on the timeline of events that take place in Skin Deep. Here are all the stories in Skin Deep, in chronological order.
Fiddler's Cave - Fall 2000
Exchanges - August 2004
Orientations - Late August–Early September 2004
Nixie Spit - September 2004
Kill Them with Kindness - Late August 2004
Reunion - Late August 2004 (Later the same day as "Kill Them with Kindness")
The One-Eyed Bear - Halloween 2004
Homecoming - November 2004
Ridiculous Creatures - Winter 2004 (perhaps early 2005)
Greetings from Dogpatch - May 2005
Illumination - June 2005
Is there anything special about the year 2004? No. Eventually, Skin Deep will have stories from many different periods, and for the timeline to work out correctly, Orientations (and by extension, Exchanges) needed to be set in a specific year. 2004 was the lucky year because 2004 was the year the decision was made.