diff --git a/generate.zig b/generate.zig
index 17e2a62464b006dda7185c6e0cbd53db38c934fd..fc914f7b763bcc34e38d2e6ebff341c883f709c6 100644
--- a/generate.zig
+++ b/generate.zig
@@ -44,7 +44,7 @@ pub fn main() !void {
             var jter = std.mem.tokenizeAny(u8, line, " \t");
             _ = jter.next().?;
             const name = jter.next().?;
-            if (std.mem.indexOfScalar(u8, name, '/') == null) continue;
+            if (std.mem.countScalar(u8, name, '/') != 1) continue;
             try zones.append(allocator, try allocator.dupe(u8, name));
         }
     }
diff --git a/zone.zig b/zone.zig
index 1b227e1cc90732389c2847bc2e375a349902efad..b1f7aeabc9c6d559bc49ce92230d564e24d00a01 100644
--- a/zone.zig
+++ b/zone.zig
@@ -21,18 +21,6 @@ pub const Zone = enum {
     @"America/Adak",
     @"America/Anchorage",
     @"America/Araguaina",
-    @"America/Argentina/Buenos_Aires",
-    @"America/Argentina/Catamarca",
-    @"America/Argentina/Cordoba",
-    @"America/Argentina/Jujuy",
-    @"America/Argentina/La_Rioja",
-    @"America/Argentina/Mendoza",
-    @"America/Argentina/Rio_Gallegos",
-    @"America/Argentina/Salta",
-    @"America/Argentina/San_Juan",
-    @"America/Argentina/San_Luis",
-    @"America/Argentina/Tucuman",
-    @"America/Argentina/Ushuaia",
     @"America/Asuncion",
     @"America/Bahia_Banderas",
     @"America/Bahia",
@@ -72,20 +60,10 @@ pub const Zone = enum {
     @"America/Halifax",
     @"America/Havana",
     @"America/Hermosillo",
-    @"America/Indiana/Indianapolis",
-    @"America/Indiana/Knox",
-    @"America/Indiana/Marengo",
-    @"America/Indiana/Petersburg",
-    @"America/Indiana/Tell_City",
-    @"America/Indiana/Vevay",
-    @"America/Indiana/Vincennes",
-    @"America/Indiana/Winamac",
     @"America/Inuvik",
     @"America/Iqaluit",
     @"America/Jamaica",
     @"America/Juneau",
-    @"America/Kentucky/Louisville",
-    @"America/Kentucky/Monticello",
     @"America/La_Paz",
     @"America/Lima",
     @"America/Los_Angeles",
@@ -106,9 +84,6 @@ pub const Zone = enum {
     @"America/New_York",
     @"America/Nome",
     @"America/Noronha",
-    @"America/North_Dakota/Beulah",
-    @"America/North_Dakota/Center",
-    @"America/North_Dakota/New_Salem",
     @"America/Nuuk",
     @"America/Ojinaga",
     @"America/Panama",