Strange date display format

We have a very strange problem which I hope someone can point me in the direction to look

We have certain documents in a database that hold values correctly in a DateTime field (we are based in the UK so the values are GDT)

When the documents are displayed in a view, the view column uses @Text(fieldname;“S0”) to display the date only as part of a longer text string. For some documents (not all), the dates are being displayed as mm/dd/yyyy. Our administrator has checked all the obvious server and workstation settings and everything appears correctly set to UK

My question is - when using “S0” as a parameter on the @Text function, is there anywhere the code will go on the server to assume mm/dd/yyyy is to be used?

TIA

Mike