src/java.base/share/classes/sun/util/cldr/CLDRTimeZoneNameProviderImpl.java

*** 176,192 ****
              return;
          }
  
          // last resort
          String id = names[INDEX_TZID].toUpperCase(Locale.ROOT);
!         if (!id.startsWith("ETC/GMT") &&
!                 !id.startsWith("GMT") &&
!                 !id.startsWith("UT")) {
              names[index] = toGMTFormat(names[INDEX_TZID],
                                         index == INDEX_DST_LONG || index == INDEX_DST_SHORT,
                                         index % 2 != 0,
                                         locale);
          }
      }
  
      private boolean exists(String[] names, int index) {
          return Objects.nonNull(names)
--- 176,206 ----
              return;
          }
  
          // last resort
          String id = names[INDEX_TZID].toUpperCase(Locale.ROOT);
!         if (!id.startsWith("UT")) {
              names[index] = toGMTFormat(names[INDEX_TZID],
                                         index == INDEX_DST_LONG || index == INDEX_DST_SHORT,
                                         index % 2 != 0,
                                         locale);
+             // aliases of "GMT" timezone.
+             if ((exists(names, INDEX_STD_LONG)) && (id.startsWith("Etc/")
+                     || id.startsWith("GMT") || id.startsWith("Greenwich"))) {
+                 switch (id) {
+                 case "Etc/GMT":
+                 case "Etc/GMT-0":
+                 case "Etc/GMT+0":
+                 case "Etc/GMT0":
+                 case "GMT+0":
+                 case "GMT-0":
+                 case "GMT0":
+                 case "Greenwich":                   
+                     names[INDEX_DST_LONG] = names[INDEX_GEN_LONG] = names[INDEX_STD_LONG];
+                     break;        
+                 }
+             }
          }
      }
  
      private boolean exists(String[] names, int index) {
          return Objects.nonNull(names)