是你无法赴约还是对方?
如果是对方,你肯定要问为什么他不能来,下次约会定在哪儿。
Could let me know why you can't keep our engagement today? maybe I make appointment with you next time ?
如果是你,可以说: 不好意思,今天临时有事,不能赴约,下周见面怎样?
Something came up! Sorry for the absence. Can we move the meeting to next week?