property Chart.ShowEmptyBars as Long
Specifies whether empty bars are shown or hidden.

Long A long expression that specifies the number of time units being added to the end of each bar.  An empty bar has the start and end dates identical.
By default, the ShowEmptyBars property is 0. Use the ShowEmptyBars to show the bars, even if the Start and End date are identical. In other words, if this property is 1, the bars will be shown from the start date to end date plus 1 unit, where the time unit is indicated by the ShowEmptyBarsUnit property. For instance, if the ShowEmptyBars property is 1, 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.