A bit more explanation for clarity..
The start time (Bars, time, samples, whatever) is
inclusive. All data from that point onwards including data at that time point.
The end time is
exclusive. All data up to that point, but not including any data
at that point.
The end time is used as a "return to start point" marker. Markers like this are actioned first before any note or other data. So as soon as the Now Time counter increments to 7:00:00 (in my example above) the first action Sonar takes is to reset the Now Time to the loop start point. This is the only way to ensure bar 6 is played in its entirety.
The same is true if you're making a selection. If you want to select bars 3, 4, 5 and 6 the selection start is 3:00:00 and the selection end is 7:00:00