We spent exactly an hour at the Siegfried and Roy's Secret Garden And Dolphin Habitat (I know this for sure because my photo of the entrance was taken at 4:14 pm and my photo of the exit was taken at 5:15 pm). This includes the time waiting for the dolphin show, and the time I spent watching the white tiger pace back and forth so I could get the perfect shot. If you skip the dolphin show, it would take you about 30 minutes to go through the entire attraction.