Is it today?

J has been confused about today, tomorrow and yesterday. We have to giggle when he starts saying is it today or is it tomorrow? I was having a conversation with him the other day and I said, "Today we are going to church." J said, "Is it today?" I responded, "Yes, it is today." He said, "I knew it was today because I saw a calendar and it said today." He continued, "Sunday, Today, Monday, Tuesday, Wednesday, Thursday, Friday and Saturday." Our week just grew by one day!!