DayPilot Pro for JavaScript 2026.4.7091

Release date: October 8, 2026

Features

• Infinite scrolling supports Auto mode: It automatically sizes the timeline, shift distance, and edge margin for the current viewport and time scale. [demo]

• New resource tree expand/collapse animation implementation: Smoother motion, improved performance, configurable timing, and optional detection of the reduced-motion system preference for improved accessibility. [demo]

• Gantt progressive time-header rendering: Enabled by default, with configurable rendering margin, offscreen cache size and scroll delay.

• Scheduler progressive time-header rendering: Enabled by default, to reduce initialization time and DOM usage on long timelines, including headers with custom React or Vue content. In most cases, this allows replacing infinite scrolling mode with a pre-loaded long timeline, in combination with dynamic event loading. [demo]

• Floating event labels support custom React, Vue, and DOM elements: The framework components defined for events are displayed in floating event labels automatically.

Improvements

Scheduler

• Infinite-scrolling demo: Updated with a configuration toolbar, API links, and scroll actions below the Scheduler. (2026.4.7072)

• DayPilot.Scheduler.infiniteScrollingEnabled: "Auto" value supported. (2026.4.7072)

• Add treeAnimationDuration, accepting milliseconds or "Auto" (default). Automatic duration adjusts to content height within 240–550 ms. (2026.4.7077)

• Resource tree animation demo: Test live animation, duration, and easing controls and resource groups of different sizes. (2026.4.7077)

• Add treeAnimationEasing, supporting "standard" (default), CSS easing keywords, and custom cubic-bezier() values. (2026.4.7077)

• Add "Auto" to treeAnimation to respect the system reduced-motion preference. The default remains true. (2026.4.7077)

• Optimization of Scheduler event loading: Automatic fast placement for rows with many non-overlapping events, speeding up loading of large datasets. (2026.4.7078)

• Optimization of Scheduler row header width auto-fit: Improved rendering performance of row header auto-fit (especially for a large number of rows and row header columns). (2026.4.7079)

• Add progressiveTimeHeaderRendering, progressiveTimeHeaderRenderingMargin, progressiveTimeHeaderRenderingCacheSize and scrollDelayTimeHeaders configuration properties. (2026.4.7080)

• Speed up time-header lookup and floating-label updates. (2026.4.7080)

• Optimization of long Scheduler timelines: Reduce timeline initialization overhead by avoiding redundant date-to-string conversions and hourly boundary calculations. (2026.4.7080)

• Keep date labels visible while React time-header components mount during scrolling. (2026.4.7080)

• Progressive Time Headers demo: Timeline presets up to ten years, plain/rich/interactive header content, animated navigation and an initialization-time readout. (2026.4.7080)

• Speed up cached time-to-pixel lookups using numeric cache keys. (2026.4.7080)

• Add read-only args.invalid to onEventMoving to report an invalid move for the primary event or any event in a multi-move operation. (2026.4.7083)

• Optimization of Scheduler scrolling: Reuse floating event content and limit floating labels to visible rows, preserving content state during scrolling. (2026.4.7086)

Gantt

• Add treeAnimationEasing, supporting "standard" (default), CSS easing keywords, and custom cubic-bezier() values. (2026.4.7077)

• Add "Auto" to treeAnimation to respect the system’s reduced-motion preference. The default remains true. (2026.4.7077)

• Add treeAnimationDuration, accepting milliseconds or "Auto" (default). Automatic duration adjusts to content height within 240–550 ms. (2026.4.7077)

• Add progressiveTimeHeaderRendering, progressiveTimeHeaderRenderingMargin, progressiveTimeHeaderRenderingCacheSize and scrollDelayTimeHeaders. Progressive rendering invokes onBeforeTimeHeaderRender on demand; set progressiveTimeHeaderRendering to false for eager behavior. (2026.4.7080)

General

• Optimization of large grids: Reduce DayPilot.Date allocation overhead and accelerate timestamp access across all components. (2026.4.7080)

• Improve HTML escaping performance by avoiding DOM allocation for strings that need no escaping. (2026.4.7080)

Fixes

Scheduler

• Fixed update() throwing an error when called without options after scrollTo() (Angular). (2026.4.7069)

• Fixed an error when dispose() is called while row-header scroll synchronization is pending (core). (2026.4.7070)

• Fixed errors when dispose() is called while deferred setScrollX() or setScrollY() requests are pending (Angular). (2026.4.7070)

• Fixed an error when dispose() is called while a scrollToResource() request is pending (core). (2026.4.7070)

• Fixed errors when dispose() is called during animated scrollTo() scrolling (core). (2026.4.7070)

• Fixed zero values of scrollX and scrollY being ignored when passed to update() (core). (2026.4.7071)

• Fixed pending setScrollX() and setScrollY() requests being lost during an unrelated update of a plain config object (Angular). (2026.4.7071)

• Validate days, infiniteScrollingStepDays, and infiniteScrollingMargin to prevent repeated infinite-scrolling timeline shifts without progress. (2026.4.7072)

• Fix an error when event resizing triggers autoscroll and an infinite-scrolling timeline shift. (2026.4.7072)

• Preserve the alignment requested by scrollTo() when navigating outside the current infinite-scrolling timeline. (2026.4.7072)

• Preserve the visible date when an infinite-scrolling timeline shifts with scale: "Week" and partial cells. (2026.4.7072)

• Ignore pending onScroll and onScrollEnd dynamic-loading completions (args.loaded()) after dispose(). (2026.4.7072)

• Prevent older dynamic-loading responses from overwriting newer accepted responses in onScroll and onScrollEnd when args.clearEvents is true, for both finite and infinite timelines. (2026.4.7072)

• Fix automatic column widths remaining stale when the container width changes before the first resize notification. [demo] (2026.4.7077)

• Fix automatic column widths after expanding or collapsing resource groups when the vertical scrollbar appears or disappears. (2026.4.7077)

• Fix an exception when dropping an external row onto an empty Scheduler or one containing only the new row placeholder. [demo] (2026.4.7079)

• Fix incorrect ranges and exceptions during touch selection on timelines with variable cell widths. (2026.4.7079)

• Preserve custom DOM, React and Vue time-header content and component state while labels float, and correctly clean up React roots. (2026.4.7080)

• Fix replacement data passed to rows.update() being lost on refresh and subsequent row lookups returning outdated data. (2026.4.7082)

• Fix events.forRange() returning incorrect events after event removal. (2026.4.7082)

• Fix stale event range queries and link endpoints after rows.update(). (2026.4.7082)

• Prevent completed Angular scroll requests from overriding later scrolling commands. (2026.4.7083)

• Prevent delayed row-header synchronization from overwriting a newer grid scroll position. (2026.4.7083)

• Preserve row-relative dates and business duration when moving events between rows with different start dates or custom end dates. (2026.4.7083)

• Apply onBeforeCellRender business flags consistently when reading cells outside the viewport, including business-time moving and row.cells.forRange(). (2026.4.7083)

• Reject business-time moves with zero source business duration or no usable target business cells, displaying a forbidden shadow without adding an explanation label. (2026.4.7083)

• Preserve event grab offsets and partial-cell start offsets when eventMoveSkipNonBusiness is enabled and the event is in the first row. [demo] (2026.4.7083)

• Cancel stale event-rendering timers after disposal, scrolling, or a full update. (2026.4.7083)

• Cancel pending touch actions when the Scheduler is disposed and preserve gestures in other instances. (2026.4.7083)

• Use the correct business calendar and shadow layer when moving events in or between frozen and regular rows, including multi-move operations. (2026.4.7083)

• Reject business-time moves when the target cannot preserve the original business duration within its row and timeline bounds. (2026.4.7083)

• Keep time header text vertically aligned when floating starts or ends. (2026.4.7086)

• Preserve event padding and vertical alignment in floating labels, with an 8px minimum leading inset for the arrow. (2026.4.7086)

• Apply the resolved contrasting font color to floating event text. (2026.4.7086)

• Preserve event-relative positions and interaction for non-floating active areas while event text floats. (2026.4.7086)

• Update bundled Scheduler themes from the current Theme Designer template, including RTL floating labels. (2026.4.7086)

• Honor scrollDelayFloats for existing labels while initializing newly rendered event and header labels immediately. (2026.4.7086)

Gantt

• Fixed errors when dispose() is called while scrollToRow() or scrollToTask() requests are pending (core). (2026.4.7070)

Calendar

• Fix an exception when calling selectTimeRange() before the first pointer interaction. (2026.4.7079)

Queue

• Fix event list corruption when tapping the Queue after reordering events using touch. (2026.4.7079)

• Fix events.remove() ignoring numeric event ID 0 and throwing when the requested ID does not exist. (2026.4.7081)

• Fix multiselect.get() returning undefined instead of the selected DayPilot.Event. (2026.4.7086)

Kanban

• Fix omitted card text rendering as undefined instead of empty content. (2026.4.7081)

General

• Fix DayPilot.DatePicker throwing when a valid date is typed before the popup is opened for the first time. (2026.4.7081)

• Include the original request in Calendar, Month, Scheduler and Gantt loading error callbacks for empty responses. (2026.4.7086)

• Fix Calendar, Month, Scheduler and Gantt collection loaders silently ignoring non-array JSON responses. (2026.4.7086)

• Fix DayPilot.Date returning incorrect results when the same timezone-bearing string is parsed in both local and UTC modes. (2026.4.7086)

• Route malformed JSON responses through DayPilot.ajax() error callbacks and reject DayPilot.Http promises instead of leaving them pending. (2026.4.7086)

• Fix DayPilot.Date accepting invalid strings such as constructor and __proto__ instead of reporting a parsing error. (2026.4.7086)

API Changes

Scheduler

• With progressive rendering enabled, prepare header content and invoke onBeforeTimeHeaderRender when a header is first needed for rendering or export. Set progressiveTimeHeaderRendering to false to restore eager rendering and callback timing. (2026.4.7080)