Well, I can explain why it was done the way it was done.
We pay for network bandwidth, right, and something about how we pay is based on the heaviest-use hour of the day. So by randomly spreading out the EPG download, we ensure that people aren't all picking "midnight" or "3 a.m." or whatever people would choose - we felt like randomly generating the time would provide a more even distribution than allowing people to choose.
We might change this in the future; I'm not sure. I know the guide team has thought about that. And I believe that there's a tool somewhere that allows you to change the EPG time - though I don't advocate doing it, of course. :-)
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