scripts to move trace file

I am not sure if this is the correct forum to post my question. It's rather unix related, but it has to do with day to day oracle administration.

I wrote a korn shell script that will run on the first of each month and put the trace file from previous month to another folder.

cd /apps/oracle/diag/rdbms/test/test/trace

curmth=`date +%m`
set -A mth Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
prevmth=${mth[$((curmth - 1))]}
curyr=`date '+%Y'`
mkdir trace_$prevmth$curyr
find /apps/oracle/diag/rdbms/test/test/trace -mtime +1  -name "*.[tt][rr][cm]" -exec mv {} /apps/oracle/diag/rdbms/test/test/trace/trace_$prevmth$curyr