=ISTEXT(A1) if the result is TRUE then it is. Looking at the sample posted there is a semi colon between the date and the time, which indicates that is could be.
If that is the case then in the adjoining column
=LEFT(A1,9)+0+RIGHT(A1,8)+0 and custom format the cell to dd mmm yyyy hh:mm:ss then drag downwards - you can now sort by this column