perl -MPOSIX -F, -lane 'print join ("," ,$F[0],strftime( "%F %T", localtime $F[1]),@F[2..$#F],$ARGV),"\n"' Your-Log-file.log

##</code><code>##

perl -MPOSIX -pe's/^([^,]+,)(\d+)/ $1 . strftime "%F %T", localtime $2 /e; s/$/,$ARGV/' Your-Log-file.log