/ bin / date pode converter a hora em formatos, incluindo segundos da época.
DATE_1="'svn info svn://server.com/reponame -r 'HEAD' | grep 'Last Changed Date' | grep -E -o \"[0-9]{4}-[0-9]{2}-[0-9]{2}\ [0-9]{2}:[0-9]{2}:[0-9]{2}\"'"
DATE_2="'ls -lt --time-style="+%Y-%m-%d %H:%M:%S" | head -n 2 | tail -n 1 | grep -E -o \"[0-9]{4}-[0-9]{2}-[0-9]{2}\ [0-9]{2}:[0-9]{2}:[0-9]{2}\"'"
if [ "'date --date \"$DATE_1\" +%s'" -gt "'date --date \"$DATE_2\" +%s'" ]; then
echo "Greater"
else
echo "Less or equal"
fi