Start your group on time. If some people are late, start the meeting anyway. If you're late for the meeting, don't make a big entrance, saying hi to everyone and running out a litany of excuses for your tardiness. Sit down and give your attention to what's going on. End your group on time.
People have busy schedules and they have other items on their agenda.
All meetings can be wrapped up within five minutes of the designated time. Don't discuss personalities after the meeting with several select members. This is called subgrouping, and it ultimately will fracture your group. Since this is the type of meeting where people reveal intimate information about their lives, be respectful and keep the information confidential. Do not discuss it later with certain members of the group or share the information outside of the group.