Today’s useful English expression is really easy.
When you want to ask someone the time or date of something, you say, “When is ~?” or “When are ~?”
Tammy: When are you going to Korea?
John: I’m going August 30th.
John: When is the movie tonight?
Jen: It is at 8:00.
John: Okay. Let’s meet at the theatre at 7:30.
Mary: When is Halloween this year?
John: It’s Thursday.