It is high time that something were done upon it.什么意思

是时候了,该对这个采取措施了.

high time 表示"紧迫时机",后面的从句用过去时(实际上是虚拟语气),表示将要做的事情.

这时候是使用它的高峰期

It is high time that something were done upon it.
有些事情必须要做了。

针对它是时候做某事了

it's high time+过去式是虚拟语气

done upon it 不是在它上的意思

It is high time that something were done upon it. ＝ 处理(针对)这事情正是时候了！

这是某事完成在它的最佳时间。