Conversion de l'heure de Gries à l'heure de Niagara Falls
21:54:31
-6
15:54:31
+7
+7
+7
+7
+7
+6
+6
+6
+6
+6
+6
+6
+6
+6
+6
+6
+6
+6
+6
+6
+6
+6
+6
+6
+6
+6
+6
+6
+6
+6
+6
+6
+6
+6
+6
+6
+6
+6
+6
+6
+6
+6
+6
+6
+6
+5
+5
+5
+4.5
+4
+4
+4
+4
+3.5
+3.5
+3.5
+3.5
+3.5
+3.5
+3.5
+3.5
+3.5
+3.5
+3
+3
+2.5
+2
+1.5
+1
+1
+1
+1
+1
+1
+1
+1
+1
+0
+0
+0
+0
-1
-1
-1
-1
-1
-1
-2
-5
-5
-5
-6
-6
-6
-7
-7
-8
-9