Lightweight Day and Night Manager

Lightweight Day/Night System

A production-ready, performance-conscious Day/Night system for Unreal Engine projects that need gameplay timing without turning every system into a ticking time bomb.

This actor drives a complete 24-hour clock, rotates a referenced world Directional Light, smoothly blends lighting and fog through dawn and dusk, and—most importantly—broadcasts time changes in a scalable, event-driven way.

No gimmicks. No hidden light spawns. No per-frame spam.

What It Does

Drives a full 24-hour in-game clock (real-time adjustable).
Rotates an existing world Directional Light (no duplicate sun actors).
Blends sun color, intensity, and fog density across day/night transitions.
Handles midnight wrap correctly.
Exposes clean, human-readable time (HH:MM).
Built for Gameplay, Not Just Visuals

This system is designed around events, not polling.
Instead of checking time every tick in every blueprint, it provides:

Hour Boundary Events
Example:
22:00 → NPCs go to sleep
06:00 → Shops open
12:00 → Ambient audio shift

Minute Boundary Events (Optional)
For systems that need finer timing without per-frame overhead.

Built-In Scheduler
Register actors/functions to fire at exact times:

05:30 → Enemy patrol shift
18:45 → Fog thickens
00:00 → Reset daily systems

All handled internally, efficiently.

Performance-Friendly by Design
No duplicate lights spawned.
References existing world actors.
Caches light/fog components at runtime.
No per-frame time spam unless explicitly enabled.
Boundary-based broadcasts only.

This keeps large projects stable as systems scale.

Blueprint-Friendly
Drop-in actor.

Assign your DirectionalLight and ExponentialHeightFog.

Multicast delegates for:
Hour changed
Minute changed
Day started
Night started
Blueprint-callable controls:
Set time
Skip to day/night
Adjust cycle speed
Register scheduled events

No C++ required to use.

Ideal For
Survival games
Horror pacing
NPC routine systems
Spawn windows
Dynamic ambience
Weather hooks
Open world simulation

If your game world needs time to matter, this gives you structure without overhead.