Time limit for playing for long hours?

I have it open nearly the whole time I am awake, and I have never had a problem.

When I'm home I've sometimes left Pokemon Go on for a long time on the charger, and I used to get some captchas, probably because I was not moving so they thought I was a scanning bot, but that's about it. No soft bans or anything. I've not had it on for as long as you though.

I'll leave the game on all day while I'm at work, occasionally catching mons and hacking pokestops when I remember, and I've never had any issues.

My favorite question of the day.....just read out loud and tell me it was worth asking....ninatic wants you to be on the app as long as possible as much as you can...increases the chances of you making purchases....as long as you are playing legit why would they care that your playing there game more

There is a catch and exp limit. No time limit i know of