Greetings from Syncfusion.
The reported case is a known scenario, and it is our current behavior of the Gantt chart. In taskData, we store only the date and time values exactly as they are declared in the data source. In contrast, currentViewData contains the validated and processed dates based on the Gantt chart’s internal calculations.
Once a record is edited, the date values in taskData are also updated accordingly. This is expected behavior.
Regards,
Sridharan