This simply depends on the the availability of time and resource, depending on which, you could spend as little or much time as you want. Ideally, you may want to dedicate half an hour at the minimum daily promoting your site. And promoting can include various activities such as tracking positive/negative reviews about your business, submitting articles, video syndication, blogging, engage in social media sites like FB and Twitter etc. It would be fair enough to say that you should make sure you do spend some time at least for monitoring and promoting your site.
0 hours and 0 minutes per day, promoting any of my sites. I simply help write the content and post on the forums. Yet, as shocking as that is, the site in my sig gets 3000+ uniques per day, simply by word of mouth, Google searches, and social networks. No need to promote if you write good content and provide valuable information. The site markets itself! As for you guys saying "5 hrs per day" or "4 hrs per day"... what do you do in those 4 hours? Do you go and leave comments in tons of websites? (in the long run that won't help much). Do you go to social networks to promote (yeah I guess that could help a bit, but wouldn't it be better if people like your site enough to do it for you?). Do you make guest posts and meet new bloggers and set up advertisement (now that could definitely help)?
From the time I wake up until the time I go to bed. Occasionally I like to eat and take a washroom break
I spend about 2 hours when I setup my method, but after that it is only 5 minutes a day. I only need to setup my method when sales drop. Which is only once a week at worse case.
If you work consistently towards promotion, you really don't have to set aside a strict number of hours a day as such. You'll start to reap benefits along the way.