Calibrate Guides
Practical, evidence-based guides on light and your day
Short reads on how the timing of light shapes your energy and sleep, and how to put it to work in a normal week. Grounded in circadian research, written to be useful.
Light
How much morning sunlight you need, and whenWhy light soon after waking matters most for your body clock, how much to aim for, and what to do before sunrise, in winter, or indoors.
Light therapy lamps: how to choose one and when to use itWhat actually matters when choosing a bright-light lamp, from lux at your real sitting distance to UV filtering and size, plus how to use one for morning light.
How to dim your lights in the evening for better sleepWhich evening lights affect melatonin most, and what to change in a living room, bedroom and bathroom, including in a shared home.
Are LED lights bad for sleep? Why cool white bulbs tell your body it's daytimeCool white LEDs and screens at night send your body clock a daytime signal. Why that happens, why warm, dim LEDs are much gentler, and how to pick bulbs for the rooms you use after dark.
How daytime light affects your sleep at nightWhy the light you get during the day changes how you sleep, how dim most indoor spaces are, and how to get more daylight on a normal workday.
What different light colors at night do to your bodyWhy blue and cool white light at night affect melatonin and your body clock more than red or amber light, why brightness and timing still matter, and what the evidence says about blue-blocking glasses.
Melanopsin: how your eyes tell your body what time it isWhat melanopsin is, how a small set of light-sensing cells in your eye set your body clock, why they respond most to blue-cyan light, and what melanopic lux means.
Sleep
How to fix your sleep schedule with light timingA practical, step-by-step way to move your sleep schedule using the timing of light and dark, whether you want to wake earlier or adapt around shift work.
Does sleeping in on weekends make up for lost sleep?Whether sleeping in on weekends makes up for lost sleep, why it makes Sunday night harder, and how to catch up without shifting your whole week later.
Environment
Energy
Why you get tired in the afternoonFeeling sleepy in the early afternoon is normal for most people. When to see a doctor, what makes the dip deeper, and what to write down for a week.
Do you need to wait 90 minutes before morning coffee?Where the 90-minute coffee rule came from, what the research shows, and how late is too late for your last cup.
Tools
- Caffeine cutoff calculatorYour last caffeine before bed.
- Chronotype quizEarly, late, or in between?
- Social jetlag calculatorHow far sleep moves on days off.
- Morning light plannerOutdoor light after sunrise.
- Jet lag plannerSleep and light, day by day.
- Night shift sleep plannerSleep and light around shifts.
- Light therapy lamp distance calculatorLight reaching you, and for how long.
Ready to make it your own?
Calibrate turns these ideas into a daily light-timing plan built around your real schedule and light access. No wearable required.