It will last only 3 days, but all the participants will be able to attend pre-conference training courses and a welcome reception with the founders on Tuesday. On Wednesday the attendants will get the opportunity to experience two days of sessions, watch the product demos, Keynotes, and really inspiring talks. After all these exciting things, everyone will celebrate the end of Summit with Bash and the hackathon, called Shipit Live.
Actually, Day 1 already passed, but you can check some info about the last 2 days of summit here: https://polontech.com/blog/what-to-do-in-las-vegas-in-april-enjoy-bellagio-fountains-go-to-the-best-restaurants-and-performances-or-visit-atlassian-summit/