I just installed City Living, Backyard Stuff, and Vintage Glamour Stuff. I haven't been playing TS4 since dine out ep came out. So it's been a while.
Today I realized I have a "Sugar Skull Display case" among my skills&activities furniture and it says I have to talk to Jasmine Holiday to unlock it. Says something about "day of the dead" and that Sugars skulls can only be acquired during the "day of the dead challenge"
I searched about this Jasmine sim and people are talking about a grow fruit and gardening.

I'm super confused.
Where do I find Jasmine Holiday ? (I spent a lot of time in community garden in Willow creek but she never showed up)
What's it all about ? How does my game know when a challenge starts and when it ends? Is it an online feature? (I never use any of the online features of this game) I'm totally curious about sugar skulls, not interested in the fruit. I don't know how they are related and what's going on... Help!

Both the growfruit and the Day of the Dead challenges are time-limited challenges that are patched in by EA. Day of the Dead was mostly in October, and growfruit was either in the spring or summer. I don't really remember the exact dates. But when it's over, it's over, though you can still unlock the things in the game using cheats. I believe you can unlock the case and the sugar skulls this way. Jasmine only appears in game during challenges, and there are different places depending on the challenge, but most of them (growfruit excepted, I believe) you can call her to your house to start the challenge. She's also been involved in "triple boost" weeks where she would give your sim a boost in something like whim satisfaction points, need reduction, work performance, etc. There was another object challenge Jasmine was involved in too, that had you hunting eggs to unlock a giant stuffed bunny around Easter. That one has been done twice, so if you don't want to use cheats, I would suggest waiting until next Halloween-ish time and I imagine they may run it again.

So can I get the skulls from debug catalogue?

Found them