Screen Curfew Calculator
Work out when to switch off phones and screens before bed to protect your sleep, from your target bedtime.
How it works
Screen curfew = bedtime − buffer · Warm/night mode = bedtime − buffer − 60 min
Bright, blue-rich light from phones, tablets and TVs in the evening can suppress melatonin and push back your body clock, making it harder to fall asleep. Setting a screen curfew — a fixed time to stop using devices before bed — gives your brain a chance to wind down. Enabling warm or night mode earlier in the evening reduces blue light for the screens you do keep using.
Worked example
For an 11:00 PM (23:00) bedtime with a 90-minute buffer, the screen curfew is 23:00 − 90 min = 21:30 (9:30 PM), and warm/night mode should kick in by around 20:30 (8:30 PM).
Frequently asked questions
Does a screen curfew really help sleep?
For many people, yes — reducing evening light exposure and stimulating content helps the brain transition to sleep. Even if devices are hard to give up entirely, dimming them and avoiding stressful or activating content close to bed can help.
What should I do instead of screens?
Low-stimulation, low-light activities work well: reading a paper book, stretching, a warm shower, journalling or quiet conversation. The goal is to keep light and arousal low as bedtime approaches.
Are night-mode filters enough on their own?
They cut some blue light but do not remove the alerting effect of engaging content or the light itself. A filter helps, but a genuine break from screens is more reliable.
Related calculators
Educational estimate only — not medical advice, diagnosis, or treatment. Individual needs vary; consult a qualified healthcare professional for decisions about hydration, nutrition, medication, or substance use.