I'm not sure if this works correctly anyway. If I supply three "Months"
2012-01-01 123
2012-02-01 234
2012-03-01 345
I get three data points but the category axis labels are as follows
4-jan, 11-jan, 18-jan, 25-jan, 1-feb, 8-feb, 15-feb, 22-feb, 29-feb
$F{Month} != null
"Total Accounts"
$F{Month}
$F{Users}