Give the evening some room
A useful event timeline makes space for the things you cannot schedule: a good conversation, a second helping, a longer goodbye.
A running order should help a gathering breathe. If every part of the evening is pressed against the next, a late arrival or a long speech can make the host feel that the whole plan is slipping.
Start with the fixed points: access to the venue, a ceremony or presentation, the meal, and the agreed finish. Then ask what must happen between them. Suppliers may need time to reset a space; guests may need time to move between rooms.
Leave a little space around transitions. Arrival drinks are also time to find a coat rack, greet a friend and settle in. The end of dinner is rarely one clean moment when everyone stands up together.
Share a practical version of the plan with the people helping you. Guests do not need every operational detail. They need to know where to go and to feel that someone is looking after the next step.