In the bash below the oldest folder in a directory is selected. If there are 3 folders in the directory /home/cmccabe/Desktop/NGS/test and nothing is done to them (ie. no files deleted, renamed) then the bash correctly identifies f1 as the oldest. However, if something is done to the folder then the bash identifies f2 as the oldest. I am not sure why or how to prevent that from happening. Thank you :).
folders in directory
f1
f2
f3
Bash
# oldest folder used analysis and version log created
dir=/home/cmccabe/Desktop/NGS/test
{
read -r -d $'\t' time && read -r -d '' filename
} < <(find "$dir" -maxdepth 1 -mindepth 1 -printf '%T+\t%P\0' | sort -z )
printf "The oldest folder is $filename, created on $time and analysis done using v1.3 by $USER at $(date "+%D %r")\n" >> /home/cmccabe/Desktop/NGS/test/log
echo "$filename"