Hello. Wondering if anyone can help me...

I am having problems with a excel graph. Data is collected from a server and a timestamp is given to the set of data. I am trying to plot the data vs. timestamp. However, the whole graph is not being utilised (along the x-axis where the dates are). The user can alter the amount of data points taken. For example, they may want readings from 01/01/12 to 31/12/12 at 12:00 each day. Therefore there would be 365 readings. Or they may want readings just over the past week. So from 02/10/12 to 09/10/12 and every 15 minutes (so approx 672). Thus, the number of readings changes based on what info the user inputs. When I right-click on the graph and click ‘select data’, the x-axis sometimes has a lot of empty cells. This could be a reason why the graph is being utilised properly and just the front (left side of the graph is used)????
What I want is for the scale of the x-axis to change automatically, based on the number of data points. So from 0-365 for first example and 0-672 (but obviously the x-axis would show the dates as per above).

Can you advise at all? It would be very much appreciated!

Thanks,

Neil