I'm impressed with the number of working people who take courses on their own time.
on (one's) own time
When one is not actively working at one's job; in one's free time. It's hard to pursue a degree on your own time when you're also working a full-time job.
on one's own time
not while one is at work. The boss made me write the report on my own time. That's not fair.Please make your personal telephone calls on your own time.