Using Custom Date Fields

Maybe I'm just misunderstanding what is happening here, but I'm trying to use the Custom Date values to put in a Birthday so that Development can have a dashboard of "Upcoming Birthdays."

Birthdays are stored as an Attribute (no problem), so I though I would just convert that attribute to a date and funnel it into Custom Date 02 in the Analytics data elements. Seems simple enough.

In the TR_ANALYTICS_ELEMENT table, I put convert(datetime, key_value, 101) in the Select, VXS_CUST_KEYWORD in the From, Keyword_no = 1 in the Where, and 1/1/2900' for the Default.

For testing, I just wanted to output a Constituent ID and the Custom Date 02 value into a Pivot Table just to see what populated. This I apparently cannot figure out how to do. The Pivot table wants to do some kind of math on the value. So, I though I'd just use a filter for any Custom Date 02 values for the month of May. Couldn't figure out how to filter by Month that field.

So, maybe I'm just not using this field correctly. Can anyone tell me how to get  a birthdate into Analytics in a way that can be used by Development? Specifically, I want to eventually assign a List filter to a Dashboard that will show birthdays for members of a Development Officer's portfolio for the current month.