Making sense of the iAd performance chart

When I log into my iTunes Connect account and look at my iAd performance and click on "requests" and set the date range to "today" to see how many adds have been requested today, this is what I see.


There's a dark grey area I think representing the time up to now. It was about 6:30 when I took that screenshot CST which means it is 4:30 PST so I think the boundary between dark and light grey is showing the current time in PST.

However, I can't figure out what the light grey area means. Is that projected ad stats for the future? I thought it might be an overlay showing me yesterday's data at the same time but it can't be because yesterday's request rate was higher at the end of the day.

If anybody could explain this to me I would appreciate it.

 

In case anybody finds this thread and they are interested in the answer to this question, I got this response on the Apple developer forums: