references/type-timeline.md

# Timeline

**Best for:** release history, project milestones, incident timelines, roadmaps, changelog visualizations.

## Layout conventions

- Horizontal hairline baseline across the middle (`stroke-width=1`).

- Tick marks at time boundaries (quarters, months, sprints) with date labels below in Geist Mono.

- Events: small filled circles (`r=4`) on the baseline. Labels alternate above and below to prevent collision, connected to the circle with a 1px hairline drop.

- Major milestones: coral circle (`r=6`) + bold Geist label.

- Time scale must be honest: if intervals are non-equal, space the circles non-equally. Don't fake linear spacing for aesthetics. Break the axis visibly if a region is too dense.

## Anti-patterns

- Equal-spacing events that aren't equally spaced in time.

- Missing axis labels ("what unit is this?").

- Crowded labels without vertical offset — illegible.

## Examples

- `assets/example-timeline.html` — minimal light

- `assets/example-timeline-dark.html` — minimal dark

- `assets/example-timeline-full.html` — full editorial