diff --git a/.idea/runConfigurations/Cleanup.xml b/.idea/runConfigurations/Cleanup.xml
new file mode 100644
index 0000000..c8727ff
--- /dev/null
+++ b/.idea/runConfigurations/Cleanup.xml
@@ -0,0 +1,8 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="Cleanup" type="CompoundRunConfigurationType">
+    <toRun name="Visual Tests" type="CargoCommandRunConfiguration" />
+    <toRun name="clippy" type="CargoCommandRunConfiguration" />
+    <toRun name="rustfmt" type="CargoCommandRunConfiguration" />
+    <method v="2" />
+  </configuration>
+</component>
\ No newline at end of file
diff --git a/.idea/runConfigurations/rustfmt.xml b/.idea/runConfigurations/rustfmt.xml
index 3030f39..21a9c83 100644
--- a/.idea/runConfigurations/rustfmt.xml
+++ b/.idea/runConfigurations/rustfmt.xml
@@ -1,6 +1,6 @@
 <component name="ProjectRunConfigurationManager">
   <configuration default="false" name="rustfmt" type="CargoCommandRunConfiguration" factoryName="Cargo Command">
-    <option name="command" value="fmt --all" />
+    <option name="command" value="fmt --all -- --config imports_granularity=&quot;Crate&quot;" />
     <option name="workingDirectory" value="file://$PROJECT_DIR$/rs" />
     <option name="emulateTerminal" value="false" />
     <option name="channel" value="DEFAULT" />
diff --git a/rs/assets/shaders/skybox.wgsl b/rs/assets/shaders/skybox.wgsl
index ba43d32..b39a17b 100644
--- a/rs/assets/shaders/skybox.wgsl
+++ b/rs/assets/shaders/skybox.wgsl
@@ -6,6 +6,10 @@ struct SkyCube {
 	face_width: f32,
 	face_rotation: mat3x3<f32>,
 	rotation: mat3x3<f32>,
+	time_of_day: f32,
+	daylight: f32,
+	sun_position: vec3<f32>,
+	moon_position: vec3<f32>,
 }
 
 @group(0) @binding(0) var<uniform> cube: SkyCube;
@@ -48,8 +52,7 @@ fn vertex(@builtin(vertex_index) vertex_index: u32) -> VertexOutput {
 fn fragment(in: VertexOutput) -> @location(0) vec4<f32> {
 	let ray_dir = ray_dir(in.position.xy);
 	let sample_dir = cube.rotation * ray_dir;
-	let daytime = (sin(globals.time * 0.01) + 1.0) * 0.707;
-	let sample_color = vec4(normalize((sample_dir + vec3(1.0))) * (daytime * daytime), 1.0);
+	let sample_color = vec4(normalize((sample_dir + vec3(1.0))) * (cube.daylight), 1.0);
 
 	return sample_color;
 }
diff --git a/rs/src/lib.rs b/rs/src/lib.rs
index ab23c39..3fd5341 100644
--- a/rs/src/lib.rs
+++ b/rs/src/lib.rs
@@ -71,7 +71,7 @@ pub fn run() {
 			player::plugin.plugfn(),
 			pickups::plugin.plugfn(),
 			settings::plugin.plugfn(),
-			planet::terrain::plugin.plugfn(),
+			planet::plugin.plugfn(),
 			ui::plugin.plugfn(),
 		))
 		.insert_resource(PkvStore::new_with_qualifier(
diff --git a/rs/src/planet.rs b/rs/src/planet.rs
index 8f44a5b..a1b8c99 100644
--- a/rs/src/planet.rs
+++ b/rs/src/planet.rs
@@ -1,15 +1,19 @@
-use bevy::{
-	math::Vec3,
-	prelude::{Component, Deref, DerefMut, Vec2},
-};
+use crate::{planet::day_night::DayNightCycle, util::IntoFnPlugin};
+use bevy::prelude::*;
 use bevy_rapier3d::{na::Vector2, parry::math::Vector};
 use serde::{Deserialize, Serialize};
 use std::ops::{Add, Sub};
 
 pub mod chunks;
+pub mod day_night;
 pub mod sky;
 pub mod terrain;
 
+pub fn plugin(app: &mut App) -> &mut App {
+	app.add_plugins((terrain::plugin.plugfn(), day_night::plugin.plugfn()))
+		.init_resource::<DayNightCycle>()
+}
+
 #[derive(
 	Component, Default, Debug, Copy, Clone, Deref, DerefMut, PartialEq, Serialize, Deserialize,
 )]
diff --git a/rs/src/planet/day_night.rs b/rs/src/planet/day_night.rs
new file mode 100644
index 0000000..370d86e
--- /dev/null
+++ b/rs/src/planet/day_night.rs
@@ -0,0 +1,52 @@
+use bevy::{prelude::*, render::extract_resource::ExtractResource};
+use std::f64::consts::TAU;
+
+pub const DAY_LENGTH_MINUTES: f64 = 20.0;
+const SECS_PER_MIN: f64 = 60.0;
+const DAY_LENGTH_SECS: f64 = DAY_LENGTH_MINUTES * SECS_PER_MIN;
+
+pub fn plugin(app: &mut App) -> &mut App {
+	app.add_systems(Update, update_day_night)
+}
+
+#[derive(Resource, ExtractResource, Clone, Debug)]
+pub struct DayNightCycle {
+	pub mode: DayNightMode,
+	pub time_of_day: f64,
+	pub daylight: f64,
+	pub sun_position: Vec3,
+	pub moon_position: Vec3,
+}
+
+impl Default for DayNightCycle {
+	fn default() -> Self {
+		Self {
+			mode: default(),
+			time_of_day: 0.0,
+			daylight: 0.0,
+			sun_position: Vec3::splat(1.0).normalize(),
+			moon_position: Vec3::splat(-1.0).normalize(),
+		}
+	}
+}
+
+#[derive(Default, Clone, Copy, Debug)]
+pub enum DayNightMode {
+	#[default]
+	Running,
+	Forced,
+}
+
+pub fn update_day_night(mut day_night: ResMut<DayNightCycle>, t: Res<Time>) {
+	match day_night.mode {
+		DayNightMode::Running => {
+			let tod = (day_night.time_of_day + t.delta_seconds_f64() / DAY_LENGTH_SECS) % 1.0;
+			day_night.time_of_day = tod;
+			let cos_tod = -(tod * TAU).cos();
+			let tod_norm = (cos_tod + 1.0) * 0.5; // Remap to 0..=1
+			day_night.daylight = (((cos_tod * cos_tod) + 1.0) * 0.5) // Linger mid-day a little longer
+				* tod_norm * tod_norm // Make night last longer
+		}
+		DayNightMode::Forced => {}
+	}
+}
diff --git a/rs/src/planet/sky.rs b/rs/src/planet/sky.rs
index 0838664..8f37a26 100644
--- a/rs/src/planet/sky.rs
+++ b/rs/src/planet/sky.rs
@@ -38,7 +38,9 @@ use bevy::{
 
 use bevy::{prelude::*, render::camera::ExtractedCamera};
 
+use crate::planet::day_night::DayNightCycle;
 use bevy::render::{
+	extract_resource::ExtractResourcePlugin,
 	globals::{GlobalsBuffer, GlobalsUniform},
 	render_graph::{
 		NodeRunError, OutputSlotError, RenderGraphApp, RenderGraphContext, SlotLabel, ViewNode,
@@ -57,16 +59,11 @@ pub struct SkyPlugin;
 
 impl Plugin for SkyPlugin {
 	fn build(&self, app: &mut App) {
-		// /// Copied from Bevy source since it's not public
-		// const SKYBOX_SHADER_HANDLE: Handle<Shader> = Handle::weak_from_u128(55594763423201);
-		// let mut shaders = app.world.resource_mut::<Assets<Shader>>();
-		// shaders.insert(SKYBOX_SHADER_HANDLE, Shader::from_wgsl(
-		// 	include_str!("skybox.wgsl"),
-		// 	"skybox.wgsl",
-		// ));
-
-		app.add_plugins((ExtractComponentPlugin::<SkyShader>::default(),))
-			.add_systems(Update, notify_skybox_changed);
+		app.add_plugins((
+			ExtractComponentPlugin::<SkyShader>::default(),
+			ExtractResourcePlugin::<DayNightCycle>::default(),
+		))
+		.add_systems(Update, notify_skybox_changed);
 
 		let render_app = app.get_sub_app_mut(RenderApp).unwrap();
 		render_app
@@ -326,6 +323,7 @@ fn prepare_sky_bind_groups(
 	fallback_image: Res<FallbackImage>,
 	render_device: Res<RenderDevice>,
 	views: Query<(Entity, &Skybox)>,
+	day_night: Res<DayNightCycle>,
 	t: Res<Time>,
 ) {
 	let s = t.elapsed_seconds_wrapped();
@@ -352,6 +350,10 @@ fn prepare_sky_bind_groups(
 					face_width: skybox.size.x,
 					face_rotation: FACE_ROTATIONS[i],
 					rotation: cube_rotation,
+					time_of_day: day_night.time_of_day as f32,
+					daylight: day_night.daylight as f32,
+					sun_position: day_night.sun_position,
+					moon_position: day_night.moon_position,
 				}
 				.unprepared_bind_group(
 					&SkyCubeUniforms::bind_group_layout(&render_device),
@@ -398,4 +400,12 @@ pub struct SkyCubeUniforms {
 	face_rotation: Mat3,
 	#[uniform(0)]
 	rotation: Mat3,
+	#[uniform(0)]
+	time_of_day: f32,
+	#[uniform(0)]
+	daylight: f32,
+	#[uniform(0)]
+	sun_position: Vec3,
+	#[uniform(0)]
+	moon_position: Vec3,
 }