I have the exact same situation, and I do find it problematic. Look at this scenario:
Toward the end of the month, as I approach my data limit, Data Sense kicks in and starts limiting what my phone does (shuts off some background tasks). This is good, because I don't want to go over my limit. On the 28th, the last day of my plan, Data Sense resets and now it thinks I've used less than 1% of my data plan, so it turns the background tasks back on, and I can definitely go past my limit (as of this writing, I have less than 25mb left).
What is now happening is that on the last day, the day on which I would most like Data Sense to kick in, it's not. And it gets progressively worse for those who have a contract date of the 29th, 30th, or 31st.
12-28-2012 07:44 AM