When does Coco tell you about the shiny trinket?

[A random player]

I'm dating Nil right now but Coco hasn't told me about the shiny trinket. I thought that he tells you about it the day after he tells you about the red rose. :/

[Catsquid]

It takes a while. He'll tell you on Spring 1st, year 1.

[A random player]

Thanks!

[Something]

That never happened to me.

[🌿 ~ Spottedleaf ~ 🌿]

You have to get to Spring 1, year 1 before Coco will do this. Coco will do this when you exit the den that morning (or whatever time it is).