You can change the x-axis setting:

1. Select the chart
2. Choose ChartOptions
3. Select the Axes tab
4. For Category (x) axis, choose Category, click OK

excelguy78 wrote:
I'm new to this forum, but I am so happy I found it. I'm having a
charting problem in Excel that has been driving me nuts! I'm creating a
chart based on weekly data. So I have a chart that is broken down by
week as follows 09/07/03, 09/14/03, 09/21/03, 09/28/03. But this week
when I entered the data for the 14th, there was a huge gap in my chart
between 09/07 and 09/14. My question is how can I get Excel to only
great a stacked graph for 09/07 and 09/14 so that they appear side by
side. It looks like Excel wants to fill in the data for the days
inbetween weeks (09/08-09/13). Hopefully somebody can help. If you need
me to attach a pic just let me know. Thanks!

--
Debra Dalgleish
Excel FAQ, Tips & Book List
http://www.contextures.com/tiptech.html