The task duration is not correctly presented on the Time Scale, specially when a task end date is close to the end period.
STEPS TO REPRODUCE
1. Add a new Project or use an existing one.
2. Create a Task on the Project.
Set a relatively short duration on the task (for instance from December 10th, 2019 to December 30th, 2019.
2. Open the Project in Gantt.
3. Change the Timescale to Quarter or Year.
The task bar in Gantt to be displayed correctly (close to the end of Q4-2019 or 2019,depending on the scale, Quarter or Year).
The task bar in Gantt is exceeding its limits and getting extended to the Q1-2020, or inside the year 2020.
This issue has been reported in the past as a Defect: CLRT-78355
SE (Sustaining Engineering) has determined this Bug will not get fixed.