diff --git a/src/field/arena.ts b/src/field/arena.ts
index 6f8e32d7ddc..20914b266b9 100644
--- a/src/field/arena.ts
+++ b/src/field/arena.ts
@@ -543,6 +543,10 @@ export class Arena {
         return TimeOfDay.NIGHT;
     }
 
+    if (Overrides.TIME_OF_DAY_OVERRIDE != null) {
+      return Overrides.TIME_OF_DAY_OVERRIDE;
+    }
+
     const waveCycle = ((globalScene.currentBattle?.waveIndex ?? 0) + globalScene.waveCycleOffset) % 40;
 
     if (waveCycle < 15) {
diff --git a/src/overrides.ts b/src/overrides.ts
index 42bcc52c09b..7a22ef01740 100644
--- a/src/overrides.ts
+++ b/src/overrides.ts
@@ -75,6 +75,11 @@ class DefaultOverrides {
   readonly BATTLE_STYLE_OVERRIDE: BattleStyle | null = null;
   readonly STARTING_WAVE_OVERRIDE: number = 0;
   readonly STARTING_BIOME_OVERRIDE: BiomeId | null = null;
+  /**
+   * Overrides the Time of Day for the given biome.
+   * Set to `null` to disable.
+   */
+  readonly TIME_OF_DAY_OVERRIDE: Exclude<TimeOfDay, TimeOfDay.ALL> | null = null;
   /** Multiplies XP gained by this value including 0. Set to null to ignore the override. */
   readonly XP_MULTIPLIER_OVERRIDE: number | null = null;
   /**