I think the average adjustment period is usually 2-4 weeks in my experience. Some are faster and some can take a bit longer. if he is part-time, it could take a couple of months though depending on how many days per week he is with you. I wouldn't allow a cocoon (I am guessing this is a baby hammock) at daycare either as there is too much potential for the child to fall out, be pushed out, etc. It sounds like it will be a slow and long adjustment if he has never been left alone or been in a playpen. Are you open to having him in a carrier on your back at busy times such as when kids are arriving and leaving? I do this with new babies and I find it helps them feel secure and safe and bond with me until they are fully used to the new routines. Good luck!