When's the last time you went 12 hours or more without a cell phone?
How long did you not have it for, what we're the circumstances, and how did you feel at the end of the distanced period?
I often forget to turn on my phone. I have a cheap throw-away flip phone. Even when it's on, I don't hear it unless it's someone I know. Default ring/message tone is silent. I was burnt out on phones decades ago so I don't miss having it on.
Bought my first cell phone a few months ago. It’s a flip phone. It lives at my desk, I do not carry it with me.
But I suspect what you’re actually asking is “when’s the last time you went 12 hours or more without an internet connection.”
I try to disconnect during weekends. I may not go without touching the phone for more than 12h as often as I wanted, but the significantly lower usage during the weekends makes a difference for me.
In prison I had no phone for the first year. Then smuggled one illegally. Not joking.