"What am I doing wrong?"
Indexing that field... the calculation must be instead unstored.
Make this a field of type calclulation (not a date field with an auto-entered calculation) and specify that the calculation be an unstored calculation or it will not automatically update as time passes.
Do you have any recommended links that I can read up on Indexing? I don't seem to quite understand the concept.
Boy, now I gotta go through my database and check all my indexed calc fields....
"oy, now I gotta go through my database and check all my indexed calc fields..."
No, I think that you do not need to check ALL calc fields, but ONLY the ones that use a Get ( ) function.