diff --git a/hm/accounts/default.nix b/hm/accounts/default.nix
index 018151d..749654c 100644
--- a/hm/accounts/default.nix
+++ b/hm/accounts/default.nix
@@ -54,6 +54,7 @@ in
             # General settings
             [{
               "mail.pane_config.dynamic" = 0;
+              "intl.date_time.pattern_override.date_short" = "yyyy-MM-dd";
             }]
 
           )) "";
diff --git a/hm/common.nix b/hm/common.nix
index 2437ef2..a40ac52 100644
--- a/hm/common.nix
+++ b/hm/common.nix
@@ -144,10 +144,6 @@
       '';
     };
     stateVersion = "23.11";
-    language = {
-      base = "en_US.UTF-8";
-      # time = "en_DK.UTF-8"; # TODO Disabled because complaints during nixos-rebuild switch
-    };
     packages = with pkgs; [
       # Terminal utils
       coreutils
diff --git a/os/common.nix b/os/common.nix
index ce8fca9..3e664e1 100644
--- a/os/common.nix
+++ b/os/common.nix
@@ -31,6 +31,13 @@
     git # Needed for all the fetchFromGit in this repo on nixos-rebuild
   ];
 
+  i18n = {
+    defaultLocale = "en_GB.UTF-8";
+    extraLocaleSettings = {
+      LC_TIME = "en_DK.UTF-8"; # Should give YYYY-MM-DD but doesn't work for browser & Thunderbird :(
+    };
+  };
+
   nix.settings = {
     experimental-features = [ "nix-command" "flakes" ];
     warn-dirty = false;