someDude
The timers are saved locally in your browser. These were added by a previous contributor so you could come back to a ticket and not lose how long you'd had the ticket open for but it was poorly implemented so we removed most of it. All that's left now is that the time tracking saves automatically to local storage. It doesn't "run" as such when the page isn't open, the progress is just saved in the browser.
I'd like to revisit it at some point but it become a contentious topic for something so simple.