Timeline

Three clocks, never one. A life and a manuscript are not on the same track here, because a reader who sees them on one track will conclude — reasonably — that the manuscript dates the life. The track comes from the clock the date is on, and nothing on the page can move a record from one to another.

The ribbons count; the marks are a selection. A ribbon's height is how many records have a date in that half-century, solid where the date is certain to within it and paler where a coarser date is spread across the range it could occupy. It is a picture of the record, not of history: the rise after 1500 is the printing press and Wikipedia's editors, not a change in the number of gods. The marks are the most widely recorded of each lane, age by age and collection by collection, favouring figures recorded in a religious role. The widest view takes each age's first choices in turn, so no age is crowded out by a denser one; zoom to an age and it draws more of its own records, with their names. Every other dated record is counted in the ribbon and findable through search.

Events follow the record. Councils, synods, schisms, crusades and trials are what Wikidata dates most densely, and most of them are Christian (383 of 457 here are in Christianity). The lane takes each collection in turn, with diminishing returns for the largest, so the rest of the world is not crowded out, and the same for a series — a conclave, then a council, then an apparition, rather than conclave after conclave. Where it is still thin, the record is thin, and nothing is added to even it out.

Houses and sites. Houses are dynasties and lineages with a recorded span; the Egyptian dynasties are most of the Bronze Age's. Sites are places with a recorded date — a founding, an opening, or the earliest record of them, which is printed "attested from" and is not a beginning. An archaeological site is hatched and never called a sacred place. A range worked out from a recorded time period is drawn pale, and only when it is five centuries or narrower: wider, it says nothing about the place.

An open end is drawn open. Most traditions here have an inception and no dissolution. A missing end usually means unknown rather than ongoing, so it is drawn as a mark that fades rather than a band to the present, which would be inventing centuries of continuity. An inception is itself a claim about a beginning, usually contested — never an attestation window.

Who is missing, and why. Hinduism, Buddhism, Shinto, Greek religion and Norse religion have no span in the traditions lane because nobody can date their beginning, so the records do not. A tradition with a founder has a date; a tradition without one does not, and this chart is a picture of that difference as much as of anything else. A figure of myth or scripture dated only by a tradition (Moses, Noah) is printed "traditionally" on its page and is not drawn here.

No year zero. 1 BCE is followed by 1 CE. The arithmetic underneath uses astronomical years so that subtraction across the boundary is right, and one module is allowed to turn those into words.