Timeline

Events across multiple tracks on a shared time axis, aligned by column.

Node types

• TimePoint — a coordinate on the time axis, rendered as an anchor dot on a horizontal baseline with the year centred below it, and a dashed vertical guide descending through the diagram to anchor Events sharing its alignGroup. TimePoints are not drawn as boxed nodes.
• Event — a thing that happened at a point in time (boxed, default: steel blue). Use alignGroup to pin it to a TimePoint's column.

Edge types

• sequence — TimePoint → TimePoint. Used by Graphviz for rank ordering but not drawn: the overlay's horizontal baseline replaces the arrows visually.
• influence — Event → Event, a cross-track or within-track dependency (dashed, constraint=false). Drawn normally.

vgraph myTimeline: Timeline "19th Century Europe" {
    // Time axis
    node t1800: TimePoint "1800" [alignGroup: "1800"]
    node t1850: TimePoint "1850" [alignGroup: "1850"]
    node t1871: TimePoint "1871" [alignGroup: "1871"]
    edge t1800 -> t1850: sequence
    edge t1850 -> t1871: sequence

    group germany "Germany" {
        node g1: Event "Napoleon defeats Prussia" [alignGroup: "1800"]
        node g2: Event "German Unification" [alignGroup: "1871"]
    }

    group england "England" {
        node e1: Event "Industrial Revolution peaks" [alignGroup: "1850"]
        node e2: Event "Franco-Prussian War impact" [alignGroup: "1871"]
    }

    edge g1 -> g2: influence "led to"
    edge e1 -> g2: influence "industrialization enabled"
}

Timelines flow left to right, and groups become visual tracks. alignGroup is what puts nodes in the same column — TimePoints are optional, and alignGroup alone suffices for alignment.

Each TimePoint renders as a filled dot on a horizontal baseline with its label centred below, and a dashed vertical guide descends through the diagram so a reader can trace from a year down to every Event in that column. The sequence arrows are suppressed, because the baseline already conveys order. A

vnotation … extends Timeline inherits this rendering.