InvalidOperationException when changing the selection in case the timeBar is in a floating RadSplitContainer and browser zoom is not 100%.

The System.Globalization namespace includes the following Calendar implementations: GregorianCalendar, HebrewCalendar, HijriCalendar, JapaneseCalendar, JulianCalendar, KoreanCalendar, TaiwanCalendar, and ThaiBuddhistCalendar. 

Consider implementing support for custom calendar in RadTimeline and RadTimeBar controls.

Introduce ability for hiding GroupControl and ItemControl for scenarios, where only Items or Groups are needed.