Snapping

Makes a drag land on a raster - the axis' own step, a fixed duration, or a pattern with an offset - so dropped work starts on a time a planner can read.

import { useSchedule, snapTime } from "@umriss-ui/schedule";

Without snap a drag lands on the fine band's step, which follows the zoom. A number is a step in milliseconds; { step, offset } counts from local midnight; false places to the minute.

Snapping shapes the ghost and so the intent; it never moves data that is not being dragged. snapTime is the same arithmetic for your own use.

Examples

Snap to the ticks

Without snap, a drag lands on the fine band's step: quarter hours when zoomed in, whole hours when zoomed out.

import { useState } from "react";
import { applyIntent, useSchedule } from "@umriss-ui/schedule";
import type { Subtask, Task } from "@umriss-ui/schedule";

const at = (hours: number, minutes = 0) => new Date(2026, 2, 17, hours, minutes).getTime();

const TOURS: readonly Task[] = [{ id: "river", name: "Riverside depot tours", color: "light-dark(#2563eb, #6b9bff)" }];

const START: readonly Subtask[] = [{ id: "T-04", task: "river", lane: "van-402", from: at(7, 30), to: at(12, 10) }];

export default function SnapToTheTicks() {
  const { Schedule, Lane, Subtasks } = useSchedule({ initialView: { domain: [at(6), at(16)] } });
  const [tours, setTours] = useState(START);
  return (
    <Schedule
      ariaLabel="A tour on the default raster"
      height={100}
      intents={["move"]}
      onIntent={(intent) => setTours((current) => current.map((tour) => applyIntent(tour, intent)))}
    >
      <Lane id="van-402" label="Van FP 402 R" />
      <Subtasks data={tours} tasks={TOURS} />
    </Schedule>
  );
}

Snap to a duration

Give snap a number of milliseconds - here half a day - and every drag lands on that raster, whatever the zoom.

import { useState } from "react";
import { applyIntent, useSchedule } from "@umriss-ui/schedule";
import type { Subtask, Task } from "@umriss-ui/schedule";

const day = (d: number, hours = 0) => new Date(2026, 2, d, hours).getTime();
const HALF_DAY = 12 * 60 * 60_000;

const PROJECTS: readonly Task[] = [{ id: "shop", name: "Online shop relaunch", color: "light-dark(#2563eb, #6b9bff)" }];

const START: readonly Subtask[] = [
  { id: "w-104", task: "shop", lane: "chloe", from: day(17), to: day(18, 12), name: "Basket keeps items across devices" },
  { id: "w-107", task: "shop", lane: "noah", from: day(18, 12), to: day(20), name: "Search results layout" },
];

export default function SnapToADuration() {
  const { Schedule, Lane, Subtasks } = useSchedule({ initialView: { domain: [day(16), day(21)] } });
  const [work, setWork] = useState(START);
  return (
    <Schedule
      ariaLabel="Work planned in half days"
      height={140}
      snap={HALF_DAY}
      intents={["move", "stretch"]}
      onIntent={(intent) => setWork((current) => current.map((item) => applyIntent(item, intent)))}
    >
      <Lane id="chloe" label="Chloe Durand" />
      <Lane id="noah" label="Noah Fischer" />
      <Subtasks data={work} tasks={PROJECTS} />
    </Schedule>
  );
}

Snap to handover times

A snap raster with a step and an offset: eight-hour watches handed over at 06:00, 14:00 and 22:00 local time.

import { useState } from "react";
import { applyIntent, useSchedule } from "@umriss-ui/schedule";
import type { SnapRaster, Subtask, Task } from "@umriss-ui/schedule";

const at = (hours: number, minutes = 0) => new Date(2026, 2, 17, hours, minutes).getTime();
const HOUR = 3_600_000;

/* Offset from local midnight, whatever the time zone. */
const HANDOVERS: SnapRaster = { step: 8 * HOUR, offset: 6 * HOUR };

const ENGINEERS: readonly Task[] = [{ id: "ada", name: "Ada Mwangi", color: "light-dark(#7c3aed, #a98bfa)" }];

const START: readonly Subtask[] = [{ id: "watch-1", task: "ada", lane: "primary", from: at(6), to: at(14) }];

export default function SnapToHandovers() {
  const { Schedule, Lane, Subtasks } = useSchedule({ initialView: { domain: [at(4), at(24)] } });
  const [watches, setWatches] = useState(START);
  return (
    <Schedule
      ariaLabel="An on-call watch on the handover raster"
      height={110}
      snap={HANDOVERS}
      intents={["move"]}
      onIntent={(intent) => setWatches((current) => current.map((watch) => applyIntent(watch, intent)))}
    >
      <Lane id="primary" label="Primary" />
      <Subtasks data={watches} tasks={ENGINEERS} />
    </Schedule>
  );
}

Place without snapping

snap={false} lets a drag land on any minute - for times that follow the pointer rather than a raster.

import { useState } from "react";
import { applyIntent, useSchedule } from "@umriss-ui/schedule";
import type { Subtask, Task } from "@umriss-ui/schedule";

const at = (hours: number, minutes = 0) => new Date(2026, 2, 17, hours, minutes).getTime();

const ENGINEERS: readonly Task[] = [{ id: "sam", name: "Sam Okafor", color: "light-dark(#0d9488, #3cc7b8)" }];

const START: readonly Subtask[] = [{ id: "window-1", task: "sam", lane: "notifications", from: at(13, 5), to: at(13, 50), name: "Maintenance window" }];

export default function NoSnapping() {
  const { Schedule, Lane, Subtasks } = useSchedule({ initialView: { domain: [at(10), at(18)] } });
  const [windows, setWindows] = useState(START);
  return (
    <Schedule
      ariaLabel="A maintenance window placed freely"
      height={100}
      snap={false}
      intents={["move"]}
      onIntent={(intent) => setWindows((current) => current.map((one) => applyIntent(one, intent)))}
    >
      <Lane id="notifications" label="Notifications" />
      <Subtasks data={windows} tasks={ENGINEERS} />
    </Schedule>
  );
}

Keyboard

The keys of First schedule apply here.

Props on this page

Every page of @umriss-ui/schedule

Getting started

• Installation
• First schedule

Plan

• Lanes
• Lane groups
• Subtasks
• Bar labels
• Appearances
• Overlap
• Dependencies
• Routes

Time

• Time axis and calendar
• Blocked time
• Milestones
• Now line
• Pan and zoom

Reading

• Selection
• Interactions
• Tooltip
• View
• Linked schedules
• The handle
• Findings as data

Editing

• Move and lane
• Stretch, lead-in, lead-out
• Snapping
• Placing from outside
• Where a subtask may go
• Ripple

Measuring

• Benchmark

API index

• API index