According to wiki, the first Zune was released on Nov of 2006.

That sounds very plausible. I've worked on software that mistakenly assumed that each date of the year was exact 24 hours (86,400 seconds) long, which is not true on days where Daylight Saving Time takes effect or ends. On those dates, the day is 23 or 25 hours long, and the software would display stuff off by an hour or in rare cases crash, because the calculations put the stuff on the next or previous date. So I think your guess has a good chance of being right.

I wonder if these reports will start taking into account usage caps employed by some ISPs. After all, what would be the point of upgrading from a 5 Mbps line to a hypothetical 500 Mbps line if your ISP caps your usage to the same number of GB in both cases? It would LOOK like ISPs are offering faster speeds, but you wouldn't be able to use that faster line to do more than you could with the slower line.