Timelines

Use a timeline to inspect a schedule’s coverage day by day. timeline(source, window) returns JSON-compatible data. renderTimeline(data) formats that data as text without evaluating the rules again.

Evaluate and render

import { renderTimeline, schedule } from "@kensio/quando";

const office = schedule({ zone: "Europe/London" }).open(
  "mon-fri",
  "09:00-17:00",
);
const from = Temporal.ZonedDateTime.from("2026-03-09T00:00[Europe/London]");
const to = from.add({ days: 1 });
const data = office.timeline(from, to);

console.log(data.days[0]?.date);
// 2026-03-09
renderTimeline(data);

Both endpoints are required. The window includes from and excludes to. A schedule groups days in its configured zone. The standalone query uses the zone of window.from.

Each TimelineDay contains its date and covered intervals. Its start and end describe the full local day. Its visibleStart and visibleEnd are clipped to the requested window.

Timestamps are strings. A day with no covered intervals is closed. A local day can span 23 or 25 elapsed hours when the clocks change.

Select an assignment

import { assigned, rota, timeline } from "@kensio/quando";

const onCall = rota().assign("mon-fri", "alice");
const data = timeline(assigned(onCall, "alice"), { from, to });

Use whereValueMatches to select object values by a field. The selection preserves an attached custom-rule registry. Timeline evaluation throws BeyondHorizonError if coverage is unknown.

The CLI exposes the same operation as quando timeline with --format json or --format text.