The two things that trip people up are:

1. UTC time, and
2. [What actions count as access.](https://meta.stackexchange.com/a/66485/1438)

The second is purposefully a bit vague, but just visiting the home page doesn't count. You need to read a question or some other action that demonstrates you are using the site in some capacity.

The first is mostly a problem if you aren't on a regular schedule. Weekends are especially tricky for me in California since I might log out on Friday afternoon before the end of the UTC day and not come back until Saturday evening. Even though I've been to the site on two consecutive _localtime days_, I've missed a UTC day.