Dates parsed by DHTMLX gantt don’t seem to be correct compared to the original MPP file which has been exported from Microsoft Project. Is MPP the preferred file type or is XML better? Can you please check and advise? Thanks
When you import MSP files, the tasks in the JSON data have only the start_date and duration properties. So, Gantt needs to calculate the end_date parameter.
In DHTMLX Gantt, the task duration and end date depend on the Gantt configuration. For example, when the work_time config is enabled, Gantt skips the weekends when calculating the duration. But by default, they are not skipped: https://docs.dhtmlx.com/gantt/desktop__working_time.html
As that will make the tasks end earlier (for example, they will have the duration of 3 hours instead of 3 days), you will need to set the end_date parameter as it has a higher priority over the duration parameter. You can obtain it from the Finish parameter in the $raw object of the imported data: