Chinese phrase
〜大约发生在什么时期？ 〜 dà yuē fā shēng zài shén me shí qī
Meaning
About when did ___ take place?
When to use it
Asks about the approximate period when an event took place. It is a neutral question about time, rather than an exact date.
Example dialogue
辛亥革命大约发生在什么时期？ xīn hài gé mìng dà yuē fā shēng zài shén me shí qī
About when did the Xinhai Revolution take place?
大约发生在二十世纪初。 dà yuē fā shēng zài èr shí shì jì chū
It happened around the start of the twentieth century.