When was the 29th Olympic Games held?---- 8:00 of August 8th

因为8：00是个钟点,钟点前应该用at,英语的介词用法非常明确,可以说是“各管各”,即由最小的时间概念决定介词, 8:00 of August 8th,2008这一短语中,8：00最小,用at; August 8th,2008中8th最小,所以用on,即 on August 8th; August 2008中,August 最小,所以用in, 即 in August 2008 ; 2008前用in