I only track time now because i have to bill them to clients, and it seems i have tracked approx 2500+ hours from December 2009, which is when i started freelancing.
And i've probably been programming since college, but really minor stuff not much beyond the curriculum. But i've always played around with new technologies, even if it was just hello world in different dialects.
I started programming when I was around 10 or so (my dad was in college for CS at the time and I "helped" with his assignments), but didn't keep it up and stopped until college.
I started programming since I started college in 1999. I am guessing around 17,500 hours.
HN has had little impact on my approaches to software development. HN has helped greatly in my understanding of the startup process which is why I frequent this place.
I started programming when I was in school... But I have been involved in professional programming (working in a firm) for 3 years now... I'm between Intermediate and Senior level... And calculating the time I've spent programming in the firm (only) it would be almost equal to 9640 hours!! :D