AnyChart JavaScript Gantt Chart supports rich tooltip customization on both the data grid and the timeline, letting you present context-sensitive information for every schedule element.
This sample creates a resource Gantt chart and configures separate tooltip formatters for the data grid and the timeline. The data-grid tooltip calculates total task duration in days from the minimum and maximum period dates, while the timeline tooltip displays the hovered period ID, index, and duration in hours. Custom title formatters add descriptive headings to each tooltip.
See the Gantt Chart documentation for all configuration options.