SSIS Expression to convert US date to ISO Date mm/dd/yyyy to yyyy-mm-dd

I developed the following SSIS expression to convert a US date to an Australian date.

(DT_DATE)(TOKEN(datestart,"/",3) + "-" + TOKEN(datestart,"/",1) + "-" + TOKEN(datestart,"/",2))

Uses SSIS's token function as opposed to substring's etc...  I've found token to be more reliable and better suited to this outcome.