Utilities

import {
  toDate,
  addUnit,
  diffUnits,
  format,
  getColumnWidth,
  computeTimelineRange,
  nextZoomLevel,
  resolveScale,
  resolveScales,
  ZOOM_LEVELS,
  PRESET_SCALES,
  getVisibleColumnRange,
  getViewportColumnRange,
  maintainBufferedColumnRange,
  filterRectsInXRange,
  DEFAULT_COLUMN_SCROLL_BUFFER_PERCENT,
} from 'react-gantt-lib';

computeTimelineRange

const range = computeTimelineRange(tasks, 'week', 2, {
  minDate: '2026-01-01',
  maxDate: '2026-12-31',
});
// → { start, end, columnCount, pixelWidth?, fixed? }

Column virtualization

Function	Purpose
getVisibleColumnRange(...)	Buffered visible column window
getViewportColumnRange(...)	Tight viewport range (no buffer)
maintainBufferedColumnRange(...)	Incremental range update on scroll
filterRectsInXRange(...)	Filter date-marking rects to x range

Zoom & Timeline guide · Performance guide