You can start on any day, depending on what fits best for you. The first couple of days are critical to your success, so pick a start date that makes sense for your schedule. You might want to look for a time when you don't anticipate any family, work-related, or other social-type events that may present additional obstacles or temptations. Let your independent OPTAVIA Coach know which day you plan to start so they can provide you with support and guidance.