Here's a timeline showing when all the Raksura stories happen. I think it's right.
"The Tale of Indigo and Cloud" - in the Reaches, before the Time of the Great Leaving
"The Forest Boy" - Moon as a young boy
"The Dead City" - Moon as a young man, after Saraseil
"Adaptation" - sometime later, at the old Indigo Cloud colony in the east
The Cloud Roads - two turns later
The Serpent Sea - eleven days later after the end of The Cloud Roads
The Siren Depths - two months after the end of The Serpent Sea
"Mimesis" - three months after the end of The Siren Depths
"Trading Lesson" - a month later
"The Falling World" - one turn since arriving at the Reaches colony
"The Dark Earth Below" - six months after the end of "The Falling World"
Timeline for the Raksura Stories
August 13th, 13:36