>It would seem that in FoxPro 2.x the best way to index a table
>on a DATE field was to index on DTOS(Fieldname) as that
>created a character based index which proved to be much faster
>in operation than a date based index where, during comparison,
>dates had in any case to be converted internally to characters by FoxPro.

It depends on your index expression. If it's a single field, you'd surely index on it as is. In case of date type fields, VFP would probably index on its Julian Day Number. If it's a DateTime, it already is a Julian Day Number (higher four bytes forming a long integer) with number of milliseconds since midnight (another long integer), and it will index probably by converting its both parts using BinToC() function, which should be pretty fast - it only adds a fixed value and swaps bytes around.

If your date (or datetime) field is part of a compound key, DTOS() is the way to go, just to make sure it gets stored in the key expression as yyyymmdd (and be Y2K compliant, as it always was).

BTW, there was a nice trick if one wanted to have a compound index on a character field plus a date field with the char part indexed ascending, and the date descending:

index on char_field+tran({^2200.01.01}-datefield, "999999") to whateverTag

Of course, if I wanted to use it today, I'd use

index on char_field+BinToC({^2200.01.01}-datefield) to whateverTag

The {^2200.01.01} notation is the new trick I learned here the other day :)