I bought a couple of packs in 6-9 months for a friend who's going to have her baby in early August.  Just in time for the baby to wear at least 3 months until it gets cooler.  They are adorable with designs.  I only wished my son was a baby again so I can get him these :).  They're also a bargain (<$9 for 5).  I hope Amazon will get more so I can buy more.