Thank you for the question.
The DateTimeCategorical axis does not support re-scaling or explicitly specifying the categories positions. I am not sure if I understand your scenario correctly, but could you please take look at the attached image. If this is what you wish your chart to look like, I have also attached the sample project. It uses a DateTimeContinuous axis and since only the minutes DateTime part is displayed, the data point with category 1h 30min goes at the place you wish your last category to be positioned.
Please, let us know if this helps.
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