Okay, now I'm a little confused as you say the files are one thing then your format is another.
I think it safest to assume you really mean it's either YYYYMMDD or MMDDYYYY

Consider this rather bald code:-

Code:

# Set the three values for the current date
date +'%Y %M %D' | read Cur_Y Cur_M Cur_D

target_dir=/tmp/${Cur_Y}_${Cur_M}      # Not sure where you want to put them

# Get last month's numeric value
((LastM=$Cur_M=1))

if [ $Last_M -eq 0 ]                   # Have we gone back from January?
then
   Last_M=12                           # Set to December
   ((Last_Y=$Cur_Y-1))                 # Take one from year
else
   Last_Y=$Cur_Y
fi

# Process files based on the expression and the date range we need
for file in ?UTO_??_${Last_Y}${Last_M}[1-3][0-9].TXT ??_?UTO_${Last_M}[1-3][0-9]${Last_Y}.TXT
do
   printf "Found file \"$file\" to move.\n"
   mv $file $target_dir
done

The last bit looks frightful but it's really just glueing the various variables together. It is looking for files in the current directory matching the two expressions. Looking at the first one, we have:-Apart from calling the date command, these are all processed within the shell, so if you have lots of files, you don't have the overhead of repeatedly calling external programs which can slow you down considerably.



Does this get you somewhere towards your need? Apologies if I've missed the point.




Robin