P’yŏngsŏng time to Piet Retief time conversion
20:10:10
-7
13:10:10
+1
+1
+0
+0
+0
+0
+0
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-2
-2
-2
-3
-3
-3
-3
-4
-4
-5
-6
-6
-6
-6
-6
-6
-6
-6
-6
-7
-7
-7
-7
-8
-8
-8
-8
-8
-8
-9
-12
-12
-12