visa days limit

hello, I would like to verify that the day limit to china for singapore passport holder is maximum up to 15 days including the day u enter china? because the china embassy official website says less than 15 days no need visa and more than 15 days need visa, and so that did not cover the information for 15days itself. As I am going to china for exactly 15 days, this becomes important to me and i would like to verify this again. kindly revert. please also let me know if this day count does not include HK? As I am going HK before china. thanks!