echo "1234">"1233" 1
echo "2011-12-08">"2011-12-07" 1
echo "2011-12-08 10:00">"2011-12-07 09:00" 1
echo "2011-12-07 10:00">"2011-12-07 09:00" 1
echo "2011-12-08">"2011-12-07 09:00" 1
echo "2011-12-08 10:00">"2011-12-07" 1

echo "1234"<"1233"
echo "2011-12-08"<"2011-12-07"
echo "2011-12-08 10:00"<"2011-12-07 09:00"
echo "2011-12-07 10:00"<"2011-12-07 09:00"
echo "2011-12-08"<"2011-12-07 09:00"
echo "2011-12-08 10:00"<"2011-12-07"

echo "2011-12-08">="2011-12-07" 1
echo "2011-12-08 10:00">="2011-12-07" 1
echo "2011-12-07 10:00">"2011-12-07" 1
echo "2011-12-07">="2011-12-07" 1
echo "2011-12-07 --:--">="2011-12-07" 1
echo "2011-12-08">="2011-12-07" 1
echo "2011-12-08 10:00">="2011-12-07" 1

echo "2011-12-06">="2011-12-07"
echo "2011-12-06 10:00">="2011-12-07"
echo "2011-12-06 10:00">"2011-12-07"
echo "2011-12-06">="2011-12-07"
echo "2011-12-06 --:--">="2011-12-07"
echo "2011-12-06">="2011-12-07"
echo "2011-12-06 10:00">="2011-12-07"