--- /dev/null
+8:12<8:13? true
+8:12<=8:13? true
+8:12>8:13? false
+8:12>=8:13? false
+8:12<=>8:13? -1
+8:12,8:13? max=8:13 min=8:12
+8:12.is_between(8:13, 9:13)? false
+8:13.is_between(8:12, 9:13)? true
+-
+8:13<8:13? false
+8:13<=8:13? true
+8:13>8:13? false
+8:13>=8:13? true
+8:13<=>8:13? 0
+8:13,8:13? max=8:13 min=8:13
+8:13.is_between(8:13, 9:13)? true
+8:13.is_between(8:13, 9:13)? true