diff --git a/deploy/nixos/configuration.nix b/deploy/nixos/configuration.nix
index 239cf53..eeabe5a 100644
--- a/deploy/nixos/configuration.nix
+++ b/deploy/nixos/configuration.nix
@@ -282,9 +282,8 @@ in
     };
   };
 
-  # Fleet default. Override per machine with timeZoneForModel in flake.nix —
-  # mkDefault is what lets that override win without mkForce.
-  time.timeZone = lib.mkDefault "America/Guatemala";
+  # Timezone - set to your location
+  time.timeZone = "America/Guatemala";
 
   # Locale
   i18n.defaultLocale = "en_US.UTF-8";
diff --git a/flake.nix b/flake.nix
index 15543ee..9fb2304 100644
--- a/flake.nix
+++ b/flake.nix
@@ -116,18 +116,6 @@
         batm3 = "USD";
       };
 
-      # Timezone per machine model. Wall-clock time on an ATM is not cosmetic:
-      # it is what the journal is read in when someone is standing at the
-      # machine, and system.autoUpgrade's `dates = "04:00"` is local, so this
-      # decides when the nightly rebuild restarts the app and the dispenser
-      # runs its audible init routine. A machine on the wrong zone does that
-      # in the middle of its own business hours.
-      #
-      # Unlisted models fall back to the fleet default in configuration.nix.
-      timeZoneForModel = {
-        sintra = "Europe/Paris";
-      };
-
       lib = nixpkgs.lib;
 
       # Helper to create a live USB NixOS config for a specific machine model
@@ -186,10 +174,6 @@
                 appDir = "${atm-app}";
               };
 
-              # Per-machine wall clock; see timeZoneForModel above.
-              time.timeZone = lib.mkIf (timeZoneForModel ? ${machineModel})
-                timeZoneForModel.${machineModel};
-
               # Operator TUI and CLI tools
               environment.systemPackages = [
                 atm-tui.packages.${system}.default