Setup > Event Planning > Timelines - Locate the timeline you wish to force. Click to open. Click "Create New Timeline" button for new timeline.
Locate "Event or Activity" section. Enter exact order in fields. Locate "Default Time" section. Enter time integers in minutes based on event start time. Do not use hours and minutes. An "event / activity" that takes place before the start time uses negative numbers and positive numbers for after the start time. Example: Event start time is 6 PM and the "event / activity" (such as guest arrival) takes place at 5:30 PM...use -30. Event start time is 6 PM and the "event / activity" (such as mother / son dance) takes place 7:30 PM...use 90. Locate "Additional Options" section. Locate "Force Timeline Order (do not use drop-downs)" field. Select "Do NOT allow the client to select the order of events". Locate "Do Not Show Times (just show activities and notes)" field. Select "Do NOT allow the client to add time values". Click "Save" button.