How do you know when you’ve spent too much time on your phone? What are things that call attention to it?

Rudra I.
I feel headache when I use my phone continuously or facing bright screen for a long time and also feel less energetic and lazy. When someone asks you what did you do today and you don't have any good answers than it proves that you might used your phone much or was facing screen for some reason whole day.
Jules S.
sometimes its when my phone tells me it has low battery, when I realize I've done 30 things on it but little times has passed, or when I focus and look at the time.
Alex Z.
I start seeing the clock that how much time i have spent on it….after wasting time on phone my inner soul automatically starts telling me stop wasting time and use it for good purpose