So here is my advice: when you prepare the agenda for your next meeting think very thoroughly who would need to be present for what part to not only have an effective meeting but make the most efficient use of everyone’s time. Clarify this with all participants and leave it up to them to join earlier and leave later if they want to do so. In that way you leave the responsibility for the time management with each person rather than being too prescriptive about how they spend their day. Looking from the other end, as a participant, ask organisers of meetings at what time they expect your point to be on the agenda for you to join the meeting in time. You could even agree that they would text you when it is your turn to present or join the discussion.
One of my clients who started doing exactly that received incredibly positive feedback from people involved about the increased effectiveness and efficiency of their time management.
And as a byproduct, chances are, the meeting agenda gets organised and planned better to start with.