从何时起的英文：
from when

参考例句：

At some point, he began hearing voices.
不知从何时起，他开始产生幻听。

Such ceremonies have been handed down to us from time immemorial.
这种仪式不知从何时起一直传下来。

Do not know to when, the home of eye wheel well into the "worm" wells.
不知道打何时起，故乡那眼辘轳水井换成了“蜗杆”水井。

Since when have terrorists and tyrants announced their intentions, politely putting us on notice before they strike?
试问恐怖主义分子和暴君从何时起宣布过他们的图谋，在动手之前彬彬有礼地向我们发出通知？

when是什么意思：
conj. 在…时候；在…之后；一…就；考虑到，既然；虽然，然而
adv. 什么时候，何时；在那时；当时
pron. 什么时侯；何时
n. 时间

Tact is the art of recognizing when to be Big and when not to be little
知道何时应该宽宏大度,何时不应量小器微,是谓练达

Time flies when you are online.
上网的时候时间过得飞快。

When you see him, book!
当他见到他时，迅速离开！

When are the telecastings broadcast?
什么时候播放电视广播？

When to violate guidelines
什么时候打破规则