how many hours

On average, probably  10 hours a month just hitting balls. My golf rounds last 4-5 hours, and sometimes I might play 2, or 3 rounds a week. So, 6 rounds a month, plus the 10 hours hitting balls, I suppose I am looking at a maximum 40 hours a month, +/-  playing/practicing. Depends on the weather. I don't watch that much golf on TV for it to even matter  Might as well add in another 30 hours a month reading, and posting on this web site. So 70 +/- hours a month????

Just practice? I'd say in the winter on average an hour every night. As the weather improves and I get more opportunities, probably two or three times that. Unfortunately, it's not always practice with a purpose.

And while you're not alone in your obsession, our spouses are right... we're crazy.

I was laughing about this one day while talking to my brother (whose not a golfer) and he put it in a pretty good perspective by saying "At least you have something in your life that you really enjoy. There are worse things you could be doing with your time."

My wife laughs at me for putting around the house while she reads. Golf is by far the most addicting hobby I've ever had. The more I play or practice the more I want to.

120 hours per month in the summer.

Winter is another matter. 0 hours in February unless you count about 5 hours putting in the basement.