RFY timing - the only constant is change

Like many of us, for quite a while now I've been getting RFY items on the hour starting at 8 PM. I didn't get something every hour, but when I did get something it was right at the top of the hour. Last night and today I had nothing in RFY, but the past two hours I've gotten something at ~37 minutes past the hour. Go figure. Is this news? Perhaps not. I'm just wondering if others are seeing the same thing tonight.

In case anyone is wondering, I got just one item each hour and they were both completely irrelevant to me.