Hi Craig,

Yes, good call. Testing is always warranted. Here, given that both of the two index key approaches,

... + str( SomeDate - AnotherDate )
vs.
... + bintoc( SomeDate - AnotherDate )

require a VFP function call, the index size seems to make some difference albeit relatively marginal. Bintoc() seemed (earlier informal tests on a local drive) to be in the range of five to maybe twenty percent faster depending on the table's size. Not enough to go back and retrofit changes.