DD6 just started first grade. She had close to the same Kindergarten schedule as your son. She took several weeks to adjust and adapt to eating lunch at school, riding the bus, long days, etc.
At Meet the Teacher night (couple weeks after school started) her Kindergarten teacher commented to the parents about naptime. It was supposed to be a 15-20 minute break after lunch for the kids to have some quiet time laying down. She said some kids could barely handle lying still for that long and some immediately fell asleep and she'd allow them to sleep a while when everyone else got back to work. After several more weeks all the kids had adjusted to naptime.
Strangely, the biggest transition was for DS2 1/2 at the time. He absolutely freaked out that big sis got to go off to school on a big bus every day. He missed her terribly and was still acting awful long after DD had adjusted to kindergarten. He actually adjusted better to starting fulltime daycare when I returned to work in January than he did to his sister starting all-day school!
At Meet the Teacher night (couple weeks after school started) her Kindergarten teacher commented to the parents about naptime. It was supposed to be a 15-20 minute break after lunch for the kids to have some quiet time laying down. She said some kids could barely handle lying still for that long and some immediately fell asleep and she'd allow them to sleep a while when everyone else got back to work. After several more weeks all the kids had adjusted to naptime.
Strangely, the biggest transition was for DS2 1/2 at the time. He absolutely freaked out that big sis got to go off to school on a big bus every day. He missed her terribly and was still acting awful long after DD had adjusted to kindergarten. He actually adjusted better to starting fulltime daycare when I returned to work in January than he did to his sister starting all-day school!