Thanks very much for the responses.

The users further complicated the issue by stating that they wanted the function to also give an offset date (negative) to the input date.

What I've done is (as per Slimdave) [many thanks], simplified the issue be populating a table full of working days.

I've also included a column of 'day_sequence', and ordered this from min date to max date.

Now, the function will derive the day_sequence for a given input date, add the (+ve or -ve) offset number of days, and then re-lookup the given working day for the sequence.

The quickest solution I thought up on the spur of the moment, but obviously involves a couple of table scans (albeit very small table).

Anyone an idea on refining my current end product?

:-)

T.