Group/Ungroup disabled in Pivot Table - Excel 2013

Hi,

I have a Pivot Table that's referencing a SQL server query as the Data Connection. The query is pretty straightforward. I just want to get a list of the usernames and the date the accounts were created.

SELECT
[Accounts].[Username],
convert(datetime,[Accounts].[DateCreated]) AS [DateCreated]
FROM
[Accounts]

I can get this working in a pivot table, but I want to group the dates by a range so I can see how many accounts were created in the month of May. This is where I'm stuck. The group/ungroup options are disabled.

Untitled.png

What I've tried:

1. I've made sure that the column is formatted by date
2. If I copy the data in the table to another worksheet and create a pivot table all works fine. I'm able to group my dates.

Is it possible that grouping and ungrouping aren't available when pulling data from a SQL query?

Kevin, if you take a look at Untitled.png you can see that "Group" is disabled.

I would if I could, but as it's connecting to a SQL server I can't give you a small sample. When I manually copy the dates onto a new table, the grouping works as expected, so I was guessing it had something to do with the SQL connection.