Hi Benjamin,
We have analyzed your query and you are expecting parent task which should be rendered from 9 to 15 which was provided in a data source. In the Gantt Chart, all the parent task is dependent on their child task. The start date and end date of the parent task will be calculated based on the minimum start date of the child task and maximum end date of the child task even parent task have a start date and end date value in the data source. From your data source, the minimum start date-time is 9 (Task 2) and the maximum end date-time is 14 (Task 3).
In Gantt, dates are validated based on the predecessor, dayWorkingTime, includeweekend, holidays. And when the duration field is mapped, the end date is calculated based on start date and duration.
In UG: For the Task 7, Start date is 4/4/2019 and duration value is 3 hence End date will be 4/6/2019. But 4/6/2019 and 4/7/2019 are week end so end date will be rendered on 4/8/2019.
In Datasource from attached screen shot: For the Task 3, Start time is 11 and duration is 180minute hence End time will be 13. But by default, value of the dayWorkingTime property is 13-14. So, end time will be rendered on 14.
Please refer the below UG links for weekend and day working time.
Please let us know, if you need further details on this.
Regards,
Logeswari G