diff --git a/home/profiles/io/default.nix b/home/profiles/io/default.nix
index de38dbba..d84e7f6a 100644
--- a/home/profiles/io/default.nix
+++ b/home/profiles/io/default.nix
@@ -23,6 +23,7 @@
     ../../services/system/power-monitor.nix
     ../../services/system/syncthing.nix
     ../../services/system/tailray.nix
+    ../../services/system/theme.nix
     ../../services/system/udiskie.nix
 
     # wayland-specific
diff --git a/home/services/system/theme.nix b/home/services/system/theme.nix
new file mode 100644
index 00000000..a24f93e2
--- /dev/null
+++ b/home/services/system/theme.nix
@@ -0,0 +1,42 @@
+{
+  lib,
+  pkgs,
+  ...
+}: {
+  systemd.user.timers = {
+    theme-toggle-dark = {
+      Unit.Description = "Toggle dark theme";
+      Timer.OnCalendar = [
+        "*-*-* 18:00:00"
+      ];
+      Install.WantedBy = ["graphical-session.target"];
+    };
+
+    theme-toggle-light = {
+      Unit.Description = "Toggle light theme";
+      Timer.OnCalendar = [
+        "*-*-* 06:00:00"
+      ];
+      Install.WantedBy = ["graphical-session.target"];
+    };
+  };
+
+  systemd.user.services = {
+    theme-toggle-dark = {
+      Unit.Description = "Toggle dark theme";
+      Service = {
+        Type = "simple";
+        ExecStart = "${lib.getExe pkgs.dconf} write /org/gnome/desktop/interface/color-scheme \"'prefer-dark'\"";
+        TimeoutStopSec = 5;
+      };
+    };
+    theme-toggle-light = {
+      Unit.Description = "Toggle light theme";
+      Service = {
+        Type = "simple";
+        ExecStart = "${lib.getExe pkgs.dconf} write /org/gnome/desktop/interface/color-scheme \"'prefer-light'\"";
+        TimeoutStopSec = 5;
+      };
+    };
+  };
+}