How do I customize the X-axis in excel to match my dataset?

[cathy]

I am trying to my x-axis to match my dataset. The axis is tied to a monthly
sampling event, however the events do not occur every 30 days. I want my
first point to match the first sample date, and so-on. Thanks!

 

[John Mansfield]

Cathy,

If I'm understanding correctly, you want to change the X-axis series from
pointing at a data range that contains months to a data range that contains
the dates that match your points. To do so, click once on your chart. In
the standard toolbar, go to Chart -> Source Data -> Series Tab. At the
bottom of the Source Data dialog box there is an input where you can change
the X axis category range.