An easier way of getting a true date value is to use the DATEVALUE function. Make your concatenated text functions the argument for DATEVALUE:
=DATEVALUE(LEFT(A1,2)&"/"&MID(A1,3,2)&"/"&RIGHT(A1,2))
You will need to apply date formatting to the cell; Otherwise it will display Excel?s internal date value for the date.
The same would apply for time-entries, but use ":" instead of "/" and TIMEVALUE instead of DATEVALUE.