Calendar & Timeline — Set up a table for the Timeline

The Timeline draws each record as a horizontal bar from a start date to an end date, and it picks those fields for you by name: a date field whose name contains a word like start, begin, from, kickoff, or open becomes the start, and a second one containing end, finish, due, complete, target, closed, or to becomes the end. If no name matches, it falls back to your first date field for the start and any other date field for the end — so any two date fields give you true spans, and clear names just decide which plays which role. The toolbar always tells you which fields it chose. With only one date field there is nothing to infer the end from, so every bar ends three days after it starts and the toolbar says End inferred (+3 days). Add a second date field to draw real spans.