一个语法结构的问题某人做某事花了多少时间it is + time + sb did sth为什么前面是is 后面是did

这是个虚拟语气,固定句型
意思是：是某人该做某事的时候了
It is time(时间) +(that)+sb+did/should do sth
it is time you went to bed
另一个固定句型
it/this/that is +序数词+time(次数)+(that)+ sb have/has done sth
it /this/that was+序数词+time(次数)+(that)+ had done sth
意思是：某人第几次做某事
例如
it is the first time I have been here.

某人做某事花了多少时间
应该是
it takes somebody some time to do something
楼主的表达不对 如果it is time for somebody to do something的意思是 是某人该做某事的时间了
somebody has done something是某人做过什么事情的意思。

这个结构的意思应该是：是某人该做某事的时候了