in Summer 2004 /in summer 2004

I'm not sure whether to capitalize summer in the following contexts:

"is expected to be available from S/summer 2004"

and

"He started working at X in S/summer 2004"

Is there a rule to this? Thanks so much.

Kerstin

[RonBee]

Say "in the summer of 2004". There is no need to capitalize summer there.