在国庆节英语用on。on用来表示具体某一天。在国庆节的例句：The mother got her children up in their new clothes on national day（国庆节那天，妈妈让孩子们穿上了新衣裳）。

on National Day的例句：Several new plays will be performed on National Day（国庆日将上演几个新戏）；We had a week off on National Day（国庆节我们放了一周的假）。