Japanese phrase
___はいつのことですか？ ___ wa i tsu no ko to de su ka
Meaning
When was ___?
When to use it
Asks about the time of a past event. It suits everyday conversations when a detail or story has been mentioned without a clear date.
Example dialogue
その旅行はいつのことですか？ so no ryo kō wa i tsu no ko to de su ka
When was that trip?
一昨年の春です。 is saku nen no haru de su
It was in the spring two years ago.