Need to group the data for 4 months

[#1]

HI all,

Need to group the data for 4 months.

please see the image below. I have attached sample .qvf file

[JonnyPoole]

= MakeDate( year(CanonicalDate), 1+ (floor(Month(CanonicalDate)-1/4)*4),1)

And sort the date dimension in the chart by numeric ascending