Assuming that this is supposed to take place in the summer (i.e. June through August), here's an overview of what we have at the moment:

Stiletto: anytime
Craccoboy: anytime
Haze: June/July
DrJones: June/July, preferably July
Shadow: July
Xion: anytime
Fquist: July/August
Disguise: anytime
Enigma: July/first half of August
Electric: July/August (exception: August 20th)
Unhit: July/August
Spaztic: July/August
BunnyElmer: July
Ri + Li: June/first week of July/first week of August
Scatman: didn't post a date, but from what I could tell from his post: anytime
Toxic Bunny: July/August
Dopeh: July/August
Aiko: August

Feel free to slap me with trout if I missed anyone in this topic. I'll edit this post when other people add their dates.