It would be fantastic if JIRA would time work while an issue is being worked on (between pressing Start Progress and Stop Progress). It would have to "sleep" during off hours, which implies a working calendar (eg, M-F from 9 to 5), and users would need an "I'm on vacation" setting so that they could easily suspend work without having to Stop Progress on every issue. Ideally, developers could have personal calendars and an optional ability to overwrite the recorded work time could be available in a permission (so that an Administrator would have the ability to fix mistakes). This is something several of our developers have asked for and as a project manager, it's absolutely my #1 priority feature request.