Seems the sequence of events has been changed for this week too.
3 days:9-Jul to 11Jul (Total 36 attempts) for 3 Commons: Tarbosaurus, Ankylosaurus Gen2, Apatosaurus
3 days:12-Jul to 14Jul (Total 15 attempts) for 3 Rares: Argentinosaurus, Amaragasaurus, Nodosaurus
1 day: 15Jul (Total 3 attempts??) for 1 Epic/Hybrid: Nodopatosaurus
Note: The event day starts around 10:15am EST US and continues till 9:15am EST past the ending day. There might be a gap of 1hr at the end where you won’t see the dinos before next set of dino spawns.
Also, though the in-app notification might say “Today is Tarbosaurus…”, you can catch either of the 3 during all 3 days. You need to look at the right park to find the one you are looking for. Smaller parks sometimes spawn just one of the types.