Session lengths vary, so you are sure to find something to suit. Day camps are typically one week long and many residential camps also offer one-week sessions. However, you'll also find lots of two-week sessions, and many overnight camps offer four-week and longer sessions; these give campers time to settle in and more fully enjoy the whole overnight experience.
The
Day or Residential? How Long? section of this website has more information and advice on determining the type of camp and session length that is best for your child.