Projects have an estimated delivery date under each reward on the project page. You can view the estimated delivery date either on the project page or under your Backed Projects list under the ‘Reward’ tab. This date is determined by project creators as their best guess for when backers will receive their rewards.
Please note that estimated delivery dates are not firm ship dates. When projects launch on Kickstarter, they’re often in the early stages of development and the project itself must first be completed before rewards can be fulfilled.