不填!
由this,that ,these,those 等用于表示时间概念的名词前,
前面往往不加介词.例如:
1) That morning he got up very early.
那天早上他起得很早.
2) What are you busy with these days?
这几天你在忙些什么?
3) We will have a big gathering this coming Saturday.
下星期六我们将进行一次大聚会.