仁爱版八年级英语教材中有个句子“Let's make it half past six”,怎么不用介词at呀?

仁爱版八年级英语教材中有个句子“Let's make it half past six”,怎么不用介词at呀? Let's make it half past six.为什么half past six前面不加at Let's make it half past six . let's make it half past eight为什么具体时间前不加介词at Let's make it half past seven中为什么时间前不用at Let's make it half past six.make在这儿当什么讲? 英语翻译when shall we meet?let＇s make it half past six Let's make it half past six.的意思是不是让我们6点半做她? at half past six It's half past six.啥意思? It's half past six(what) “make it 后面直接+时间不用介词”"用法六 表示约定时间".”Let’s make it at seven o’