Group by Issues with date field when using power query

Hello,

I am having trouble grouping by date when using power query to import data from an excel file.  The group by option is grayed out.  If I open the excel file and create a pivot table with the data directly the group by date option is available which leads me to believe that the problem is not with the data in the date field.

I will have updated data regularly and want to use power query to create a link so that I can create a pivot table one time rather than having to create a new pivot table each time I export data.

Any help would be greatly appreciated.

thanks