Yap.Town

はいつなの

when is ...?

→ は
phrase Uncommon #18,002
when is ...? A casual way to ask when something is happening. The surrounding context supplies what “...” refers to.
JA: 次の会議はいつなの？
EN: When is the next meeting?

日本に来たのはいつなの？

When did you come to Japan?

手術はいつなの？

When is the surgery?

— Arrietty (2010)