By default, the ShowEmptyBarsUnit property is exDay. This property has effect only, if the ShowEmptyBars property is not zero. For instance, if your chart displays seconds, the ShowEmptyBarsUnit property must be set on exSeconds, else else if the ShowEmptyBars property is 1, the ending date for each bar is not show correctly, as 1 day is added to a second.  For instance, if the ShowEmptyBars property is 1 and ShowEmptyBarsUnit is exDay, a task bar from 1/1/2001 to 1/2/2001 shows two days, else if the ShowEmptyBars property is 0, the same task bar highlights only a single day. Use the AddBar method to assign a bar to an item. Use the ItemBar(exBarStart) and ItemBar(exBarEnd)  properties to specify the start and end dates for a bar.