“在那天”是on the day还是in the day?

“在那天”是on the day还是in the day? 是in theday还是on the day 是in the day time还是on the day time 是on the open day还是in the open day “在第一天”是on the first day还是in the first day 英语中,节假日前是用什么介词呢?比如说在五一那一天,是in the May Day,还是on the May Day? in the day还是on the day? 在同一天是on the same day还是in the same day?要准确的…… 英语中,在那天怎么表达?是用on that day 还是不用on 在休息日是on the day off 还是in the day off 或者是其他,就是说day off前面的这个介词是什么?,急 是in the second day 还是on the sencond day?快 是 in the national day还是 on the national day?如题 是on the morning of Mother's Day还是in the morning of Mother's Day? 是in the opening day,还是on the opening day.急用 in the second day 还是on the second day? on the first day还是in the first day in the raining day还是on the raining day in the day 还是on the day 题目是这样的 We have a party（）the day.