Time blocks help attendees visualize their schedule in context of your meeting. For example, users may not realize you have a 6am early morning yoga session but would notice it when checking their itinerary in the visual schedule view. 

EventPilot allows attendees to schedule as many concurrent sessions as they want. When looking at the schedule view, attendees will be able to see up to 3 individual concurrent sessions, however, if an attendee schedules 4+ concurrent sessions the time block becomes one block for a better UI experience.