Happy IoT Day! 
The organization that promotes this started in 2010, but it’s never gotten a lot of traction although it’s definitely worldwide with events from Nigeria to Sweden.
It seems to mostly be an opportunity for sensor and chip manufacturers to highlight new products that are actually available for sale, and most of the talks are highly technical and engineering focused.
No indication I can see that Samsung participates or many of the big cloud companies. Just lots of discussions on tiny devices and big trends. The following is a typical event:
Mrinal Wadhwa, CTO of Ockam, will talk about how Decentralized Identifiers, Verifiable Credentials, and Decentralized Key Management enable highly secure and reliable systems of connected devices.
But if you’re into that sort of thing, it’s today. 
The most profound technologies are those that disappear. They weave themselves into the fabric of everyday life until they are indistinguishable from it.