The useful screen insight is timing, not blame.
daygauge does not read screen time or phone pickups. You can log a late-screen habit in Quick Log and compare it with your sleep timing and recovery readings.
Start with what your own data can show.
People search blue light and screen time because they suspect their phone is changing their sleep.
Timing is the part you can check without blame: what happened on nights you logged late screen use, how often, and whether your sleep timing shifted.
daygauge does not measure screen time or pickups. Log a custom habit such as screens after 11pm in Quick Log, and daygauge shows those nights against your usual sleep window.
What this guide covers.
How the app handles this.
What this can look like in the app.
Example: on 4 nights you logged late screens, your sleep started 47 minutes later than your usual window.
ExampleConfidence rises when the same pattern repeats against your own baseline and drops when key signals are missing.
Try one small change, log it, then see whether the pattern repeats over the next week.
Example 1
Example: on those nights you also slept 32 minutes less than your average.
Example 2
Example Quest: log screens off by 22:00 for three nights and compare your sleep timing.
Further reading.
These studies describe groups of people. They help explain the topic, but they cannot tell you what will happen to you.
- Frontiers in Neurology 2025 review of blue-light blocking glasses and sleep
- npj Biological Timing and Sleep 2025 review of light and the circadian clock
- BMC Public Health 2025 sunlight and sleep timing study
Research context only. daygauge does not diagnose, treat, prevent or predict disease risk. Personal medical concerns belong with a qualified clinician.
What daygauge does not do.
Related guides.
Want to see whether late screen timing changes your next day?
daygauge is free to download. Pro is £8.99 a month or £49.99 a year.
Download on the App StorePersonal analytics, not medical advice