I've been using Taskwarrior in conjunction with Timewarrior to track time spent on work tasks. I used to be skeptical about it but the whole command-line first,

I've been using Taskwarrior in conjunction with Timewarrior to track time spent on work tasks. I used to be skeptical about it but the whole command-line first, spartan interface does wonders at keeping me focused. Better yet: it allows to set up work hours so I don't have to stop a task whenever I'm no longer working.