Hello Boris Kudryashov,
The current version of RadTimeBar for WPF does not support this. Basically, the control calculates the size of the labels and determines on each resize/zoom operation which view is the best current view, depending on the Intervals collection and the available size. You can use the IntervalSpans property of an interval to customize its duration and the FormatterProvider property to customize the strings that an interval displays.
In case this information does not help you, please provide more details on your scenario and I might be able to suggest a way to achieve the desired behavior.
the Telerik team