Hey eMax,
This should be possible, you might not have found the correct property yet.
The User Manual page for the component is massive, in this case it is easier to find what you're looking for by testing in the Designer. In the Designer, in Preview Mode, if you create a range selection you can look inside the props at the interaction.rangeBrush.values array. Here you will find objects that represent the range brush, including a start and end, so you can then calculate the time range value.
More information on the interaction properties is in a specific table on that User Manual page: Perspective - Power Chart | Ignition User Manual
For displaying the range, you can then format the time value using an expression binding and some sort of label. If you use multiple ranges you may need a more dynamic system like a flex repeater of labels.