tl;dr - here's a thing to help you explore within the limits you set yourself
@eviltester* just asked me where I keep my session timer.
I don't appear to keep it anywhere.
Sorry about that. Fixed now.
If you want to use it**, try this page: http://www.workroom-productions.com/2timer.html
I use it*** to keep me on the rails. Here's how:
If I've decided that an exploration is worth 60 minutes of my life, I load it up, change the number in the circle to 60, and hit start. If the phone goes or someone arrives, I hit pause. I want to see how much of my gamble budget I've used, because that knowledge changes the game. Proportion matters more than minutes. Various numbers show up for reasons useful to me – elapsed time, excess time. There are two (pretty much identical) timers, because I run distractions as mini sessions.
I don't want to change the timer while it's going, and I don't trust my hands to avoid the error, so I've made it so one can't (easily) change the timer while it's going. It doesn't go bing because 1) I don't care that much if I go a bit long and 2) I have a timer, so I already know. If you change the system clock, it won't complain, but it won't be much use either, and midnight's not well handled****.
If you work in a similar way to me, it may be handy. If not, it won't.
The timer is ten years old, and can be a bit of a pain with CPU as it's written in AS1 and published for Flash 5. The world and his dog uses iOS now, or HTML5/JS, or if stuck in flashland (as I am) AS3 and FP10+. Use as you wish. Feedback always gratefully received.
* also eviltester.com and elsewhere if you dig a little
** a more-useful-for-work version than the one I deploy in my workshops
*** if I use it. I don't use sessions for testing so much. I do use timed sessions for exploring documentation, investigating ideas, writing, prototyping, rehearsing and sketching. And (non-IT use) cooking, of course. For that, I use a kitchen timer.
**** Hint: it may be time to go to bed.