Basically, the RadTimeBar does not manage the positioning of the RadSparkLine according to its period range, and you need to do this manually. In order to avoid shifting, you need to set SparkLine XValues for the TimeBar.PeriodStart/End dates, so that the SparkLine start and end will match the TimeBar PeriodStart/End. In the attached file you can find a sample project that demonstrates the described approach.
I hope that this information helps.
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