diff --git a/nix/flake.lock b/nix/flake.lock
index 6ab7ab4..d303928 100755
--- a/nix/flake.lock
+++ b/nix/flake.lock
@@ -214,11 +214,11 @@
     },
     "nixos-hardware": {
       "locked": {
-        "lastModified": 1777917524,
-        "narHash": "sha256-k+LVe9YaO2BEPB9AaCtTtOMCeGi4dxDo6gt4Un3qoPY=",
+        "lastModified": 1778143761,
+        "narHash": "sha256-lkesY6x2X2qxlqLM7CT2iM/0rP2JB7fruPN3h8POXmI=",
         "owner": "NixOS",
         "repo": "nixos-hardware",
-        "rev": "df7783100babf59001340a7a874ba3824e441ecb",
+        "rev": "3bcaa367d4c550d687a17ac792fd5cda214ee871",
         "type": "github"
       },
       "original": {
@@ -261,11 +261,11 @@
     },
     "nixpkgs-darwin": {
       "locked": {
-        "lastModified": 1778030758,
-        "narHash": "sha256-8TXoMiLNpcYoKtglB6VK3zgcFw2elthUOL/1bmLBTkA=",
+        "lastModified": 1778111371,
+        "narHash": "sha256-L3LdhmeKcBrMVxqeEHwfwA1FFVf40DDCAOV8S0+PlLc=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "e3f3598f6dcc165901cf6e07d0f7c22a09df6b1c",
+        "rev": "25b257cc037722030ae920bba7c167d4db554a10",
         "type": "github"
       },
       "original": {
@@ -366,11 +366,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1778037418,
-        "narHash": "sha256-EZnAOkPgEeOO2rCRhwkTvesCq/E6dbsyxhMyaefgIWM=",
+        "lastModified": 1778123869,
+        "narHash": "sha256-hV9D8ET33kXjdoMXBT2bwM/j8WQM1SP/dVKZtjQKhAQ=",
         "owner": "oxalica",
         "repo": "rust-overlay",
-        "rev": "adf987c76af8d17b8256d23631bcf203f81e1a63",
+        "rev": "592e5dedf04f0eaff1ed0f01ce5db7407d9fc7be",
         "type": "github"
       },
       "original": {
@@ -412,11 +412,11 @@
         "wasm-bodge-src": "wasm-bodge-src"
       },
       "locked": {
-        "lastModified": 1778098111,
-        "narHash": "sha256-sRwQzFpxI2QNx1yTNDTlMYGmKEFhGztbSRoOs7iUQVw=",
+        "lastModified": 1778174611,
+        "narHash": "sha256-6G/C7dKSiRJlQYjmE3wWFD+O2f1f2+tXscTzh/l1nwE=",
         "owner": "inkandswitch",
         "repo": "subduction",
-        "rev": "9012df9d6da038354b1c8b07532620d91a57e828",
+        "rev": "fa0ab0dd011c260b71c9725bcb816d251877931a",
         "type": "github"
       },
       "original": {
@@ -487,11 +487,11 @@
     },
     "unstable-pkgs": {
       "locked": {
-        "lastModified": 1778036283,
-        "narHash": "sha256-62EWg6lI0qyzm7oAx5cAnGkLutvJsRBe0KkEW2JDZCE=",
+        "lastModified": 1778124196,
+        "narHash": "sha256-pYEytCNic/czazbV9r3tbQ6BZzqRBg/41x2dIC5ymOo=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "ed67bc86e84e51d4a88e73c7fd36006dc876476f",
+        "rev": "68a8af93ff4297686cb68880845e61e5e2e41d92",
         "type": "github"
       },
       "original": {
diff --git a/nix/modules/home/hosts/mocha.nix b/nix/modules/home/hosts/mocha.nix
index 85e6bad..30ee9cd 100755
--- a/nix/modules/home/hosts/mocha.nix
+++ b/nix/modules/home/hosts/mocha.nix
@@ -349,6 +349,14 @@ in {
             spacing = 1;
           };
         };
+
+        # Metric units everywhere — this is Canada, not a Fahrenheit-using country.
+        # 24-hour clock for the same reason.
+        services = {
+          useFahrenheit = false;
+          useFahrenheitPerformance = false;
+          useTwelveHourClock = false;
+        };
       };
 
       cli = {
diff --git a/nix/modules/home/hosts/wisteria.nix b/nix/modules/home/hosts/wisteria.nix
index 3889c2a..0e88fd5 100755
--- a/nix/modules/home/hosts/wisteria.nix
+++ b/nix/modules/home/hosts/wisteria.nix
@@ -497,6 +497,14 @@ in {
             spacing = 1;
           };
         };
+
+        # Metric units everywhere — this is Canada, not a Fahrenheit-using country.
+        # 24-hour clock for the same reason.
+        services = {
+          useFahrenheit = false;
+          useFahrenheitPerformance = false;
+          useTwelveHourClock = false;
+        };
       };
 
       cli = {