My four year old is starting kindergarten. He is young for his age and has some sensory processing difficulties. What can i do to make his adjustment period easier? His program is all day, every day - with no nap. He is coming home exhausted and very grumpy.
I'm answering this assuming that your son doesn't mind going to school–that he doesn't throw a fit in the morning and seems okay with going in. I'm also assuming that he doesn't have major behavioral issues during the day, just after school.
If that's the case, then there isn't much you can do. He's having to put a lot of effort into meeting expected behaviors at school, and its wiping him out by the time he gets home. He's used up his "being good" points for the day, and he needs to restock them!
He might need a bigger snack than usual, or one with more sugar (I'm thinking fruit, not candy). Or it might help to move dinner forward... my kids usually feel better after dinner than they do before. If he has afternoon chores, lighten that load.
You could also try reading a favorite (calming) book, making sure that the house is quiet and cool, reducing light levels, or establishing a "healing place". A grumpy kid might just need a little alone time to relax. Is there music he especially likes? It might help if that music was playing in the car or when he comes home.
Outside of that, time. He probably isn't quite used to this new place and new routine. When my son was three, we changed his daycare to a Montessori school. It took him a couple of months to fully adjust to the new school. He liked going, but when we picked him up in the afternoon he was just wiped out and cranky... and that was with a nap. It got better as he got more familiar with the new place and new expectations and it was easier for him to deal with his day.