I have on purpose been visiting every day on SO, including weekends for a few weeks now. I read and comment on questions, answering them when I can, but I am on in the morning and at night every day, and sometimes into the wee hours of the morning. I know I have not missed a day and yet the counter still resets. What am I doing wrong?
Stack Exchange uses UTC time to determine when days pass. You seem to "miss a day" a lot over weekends (at least in Stack Exchange Time). So I would speculate that you are changing your routine of visiting the site over the weekend.
If you visit the site early on a Saturday (for example), and then not again until late in the day on Sunday, it is easy to "miss a day" (a 24-hour window) in Stack Exchange time.
According to Jeff's post, a visit requires more than just visiting the login and "home page style pages" (which are not defined).
For your visit to count toward your consecutive days, you will need to dig more deeply into the site. Details are scarce, but I assume that these would not be considered "home page style pages":
- The review queues
- The question/answer edit pages