I know this site has users from all over the world, but americans are majority. (right?) i'm posting from Europe ( GMT for example). That is somewhere around 5 to 8 hours diff compared to US time zones. So i'm thinking that posting questions in the morning from 10 am to 1 pm (in Europe ), will not get that many views/answers from US users since that interval means it's night or early morning over in the US.
What also matters is when you respond to opinions as well. You can post the question whenever, get some opinions... but a good technique is to wait until what you think is PEAK time to start commenting on opinions... that way it gets bumped back into LIVE FEED and hopefully will get more opinions then.