SMART HOME BUTLER · MASTER BEDROOM
The light two hours before bed decides when you feel sleepy
Switching the light off is not the start of sleep, it is the last step of it. What really sets your bedtime is whether the whole room has been winding down since eight in the evening.
A bright white room tells your body it is noon
Besides the cells that let you see, your eyes carry a second, smaller group. They do not care what you are looking at. They report two things only: how bright it is, and how much blue is in the light. That report goes to the part of the brain that runs your body clock, and that is what decides whether melatonin gets released. Melatonin is what makes your eyelids heavy and your body ready to lie down.
The trouble is that a typical ceiling light sits somewhere between 4000K and 6000K. Translated into everyday terms, that is midday sun. You finish an episode, take a shower, walk into the bedroom and lie down, and every step of that journey has been telling your eyes that it is still daytime. Switching off at the last moment is like announcing that the sun has only just set. Melatonin starts from that moment, so of course you spend another half an hour to an hour turning over.
Colour temperature is measured in K, and the smaller the number the warmer the light. 5000K is midday, 3000K is late afternoon sun, 2000K is candlelight. You do not need to memorise any of that. One direction is enough: later in the evening, smaller number.
This is about the whole room, not one lamp
Plenty of people read "dim things down before bed" as turning the bedside lamp low. But the two hours before bed are spent in the whole room, not in the thirty centimetres around your pillow. The ceiling light hits your face, the desk lamp lights a screen, the cove lighting bounces off the wall, and the street lamp outside leaks in all night. Added together, that is the signal your body receives.
So this setup has four things to deal with: the ceiling light, the bedside lamp, the indirect lighting and the curtains. Skip any one of them and the other three lose most of their effect.
What the four hours before bed should look like
Here is the same chart written out. This is someone who goes to bed at half past eleven, and what actually happens in the room.
- 20:00
The descent begins
Colour temperature moves from 4500K to 4200K, brightness from 100% to 92%. You will not notice this step at all, and that is exactly the point. Every step is small enough to be invisible; only four hours of them add up to something you can feel.
- 21:00
The ceiling light steps back
3600K, 78%. The main light starts handing over to the indirect lighting. Light now arrives bounced off walls and ceiling instead of aimed at your eyes, and that single change does more for eye comfort than the dimming itself.
- 22:00
Your body gets the message
2700K, 45%. The room reads as dusk. The curtains come down here, shutting out the street lamp and the illuminated sign across the road. Melatonin release starts around this point.
- 23:00
Only the bedside is left
2200K, 20%. The ceiling light is off, the indirect lighting is barely there, and the bedside lamp is enough to read by without glare. Your phone screen will suddenly look very bright, which is a good sign: the room genuinely is dark now.
- 02:30
Up in the night
The occupancy sensor sees someone leave the bed and brings the low-level lamp up to 5% at 2000K. Enough to see the floor, nowhere near enough to convince your body that morning has arrived. Two minutes with no movement and it switches itself off.
Four things it takes care of
Sleepy sooner
Nothing forces you to sleep. Your body simply gets ready earlier, and the turning-over stretch after lights out gets noticeably shorter.
Nights stay nights
No white light in the face at 2am. You get back into bed and usually drop off within minutes instead of lying awake until dawn.
Easier on the eyes
Eyes are more sensitive late in the evening. Removing the direct, high colour temperature source cuts the strain from reading or scrolling.
Nothing to remember
Nobody has to dim anything, close the curtains, or feel for a switch in the dark. The whole sequence runs itself.
Before and after
| Moment | How it goes now | How it goes after |
|---|---|---|
| Two hours before bed | Ceiling light full on, midday colour | A small step down every half hour, unnoticed |
| Getting into bed | Everything off at once, eyes adjusting | Only the bedside glow left, the switch is a formality |
| The street lamp outside | Leaks in all night, nobody closes the curtain | Curtains come down by themselves at ten |
| Bathroom at 2am | Ceiling light on, awake for an hour | Low floor light, off again in two minutes |
| A partner on a later schedule | Their light wakes you up | The room is already warm and dim, so it barely registers |
What you need
Home Assistant treats every device in the house as an entity. Brand and model do not matter; what matters is the category it lands in. If you have the ones below, you can build this.
| Purpose | Category in the system | Required? |
|---|---|---|
| Ceiling light | light, ideally colour adjustable | Yes |
| Bedside lamp | light | Yes |
| Cove or shelf lighting | light | Nice to have |
| Knowing someone got up | binary_sensor occupancy | For night lighting |
| Curtains | cover | Nice to have |
| Getting alerts | notify phone app | Recommended |
How the system works
Broken apart, there are only two threads. One handles the four hours before bed, the other handles the trip in the night. They never interfere with each other, but they share the same set of lights.
Use the ready-made logic in the middle
The hub ships with a set of tested automation blueprints. Think of a blueprint as a fill-in-the-blank form: the boxes are already drawn, you only supply the answers. The evening thread uses adalight, which exists precisely to walk a group of lights along with the clock.
| Box to fill | What goes in it | Suggested |
|---|---|---|
| Which lights | Ceiling, bedside and indirect, all selected together | — |
| Start time | Four hours before you normally turn in | 20:00 |
| Starting colour and level | How the room looks when you first switch on | 4500K · 100% |
| Ending colour and level | How it should look as you lie down | 2000K · 10% |
| Time between steps | Shorter intervals feel smoother | 30 minutes |
Fill in those five boxes and the whole evening is handled. You never write eight separate rules saying "at this time set that light to this level", and you never work out the intermediate values yourself.
Different homes, different numbers
Those are general defaults. If your schedule looks nothing like that, adjust as below.
| Your situation | Start | End | Why |
|---|---|---|---|
| In bed by 23:30 | 20:00 | 2000K · 10% | The general case, use it unless you have a reason not to |
| Not asleep until 01:00 | 22:00 | 2000K · 10% | Shift the whole thing two hours later, or it bottoms out far too early |
| Shift work, no fixed hours | Four hours out | 2000K · 10% | Trigger it by voice or a phrase rather than tying it to the clock |
| You read in bed | 20:00 | 2200K · 25% | Keep the bedside lamp higher, let everything else go all the way down |
| Young children at home | 18:30 | 2000K · 8% | Children react more strongly to light, so start earlier and finish lower |
The trip at 2am, without waking yourself up
Evening light decides when you fall asleep. Night light decides whether you get back to sleep. Both matter, and the second one usually gets forgotten.
Your body is unusually sensitive to light in the small hours. The same lamp you would call ordinary at noon is enough at two in the morning to shut melatonin down on the spot. When someone says "one trip to the bathroom and I was awake for the rest of the night", the cause is rarely the bladder. It is the ceiling light.
The answer is the binary_sensor_trigger_light blueprint: occupancy triggers a light, but the light in question is the low one near the floor, held at 5% brightness and 2000K, switching itself off after two minutes of stillness. Three details carry the whole thing. The source has to be low, so it lights the floor rather than your face. The level has to be small enough to show outlines and nothing more. And it has to be limited to night hours, because walking in during the day should not set it off.
Four optional extras
Two blueprints cover the core. These are additions, so take whichever you actually want.
| If you want | Blueprint | What it does |
|---|---|---|
| The same thing in reverse each morning | adalight | Build a second one going the other way: start dim at 2000K and reach 4000K at full over thirty minutes. Gentler than an alarm, and most people who try it never go back |
| Curtains that follow the lights | light_sync_cover_and_fan | Ties the curtains to the lights, so they close once the room drops below a given level. No separate schedule to maintain |
| To switch modes with a sentence | voice_trigger_things | Say "bedtime" to Assist and the room jumps straight to the lowest step instead of waiting for the clock |
| A nudge when the curtains stay open | entity_state_trigger_notify | Sends a phone notification if the curtains are still open past eleven. Sometimes something is jamming them, and it is better to know |
You do not have to set it up, just say the word
None of this needs clicking through by hand. The WOOWTECH hub ships with HA-MCP, which lets AI connect straight into your system, build the thing, and then go back and check that it really works.
Prompts you can copy straight over
Every block below can be copied whole, using the button on the right. Pick the one closest to what you want rather than using all five.
Set up a warm evening mode in the master bedroom. From eight in the evening, have the lights in there get gradually dimmer and warmer, so that by around eleven they are at roughly ten per cent and about two thousand kelvin. Keep it smooth, with no visible jumps between steps.
Build me the whole warm evening setup for the master bedroom. Starting at 20:00, bring the ceiling light, bedside lamp and indirect lighting down together, one step every thirty minutes, from 4500K and 100% all the way to 2000K and 10%. At ten, close the bedroom curtains as well. Then add night lighting: between midnight and six in the morning, if the occupancy sensor sees movement, bring the low light near the floor to 5% brightness at 2000K, and switch it off again after two minutes of stillness. Never turn the ceiling light on for this. No spoken announcements. If something needs telling me, use a phone notification. Once it is built, test it yourself, confirm it really works, and then tell me which devices you used.
I am usually not asleep until about one in the morning, so having the room fully dark by eight is far too early. Shift the whole master bedroom warm evening sequence two hours later: start stepping down at ten, and reach the darkest step at one. Move the night lighting window as well, to two until eight. Leave everything else exactly as it is.
The bedroom was too dark by ten last night while I was still reading. Push the time it reaches the darkest step back by one hour, and raise the minimum brightness of the bedside lamp alone from 10% to 25%. Leave the ceiling light and the shelf lighting exactly as they are.
Walk me through everything the bedroom lighting did last night. Lay it out in time order, the clock time, the lamp that moved, and the brightness and colour temperature it landed on. If a step was skipped, mark it and say plainly why it never happened. Change nothing for now, I want to read the list first and then decide.
Common questions
Is reading under warm light bad for my eyes?
I often go to bed after midnight. Is this still worth it?
My lights only dim, they cannot change colour
Is 5% too dark to be safe at night?
My partner and I keep very different hours
Do I have to rebuild it to change the timing?
Two weeks from now
You turn over fewer times after lights out, the trip in the night stops leaving you awake until dawn, and the morning needs one alarm instead of three.
And in those two weeks, you have not touched a light switch in the bedroom once.