一段英语短文中的一个句子解释----高手帮忙

一段英语短文中的一个句子解释----高手帮忙When I was a boy growing up in New Jersey in the 1960s,we had a milkman delivering milk toour doorstep.His name was Mr.Basille.He wore a white cap and drove a white truck.As a 5yearold boy,I couldn't take my eyes off the coin changer fixed to his belt.【He noticed this one day during a delivery and gave me a quarter out of his coin changer.】我想知道,【】里的句子中He noticed this one day during a delivery and ----中的this与one day之间是不是应该有个逗号,如果没有的话,断句是从this结束吗?