a fellow poster, reported yesterday that they contacted the help desk and was told clues "do not" have to be posted at any required times, only that there will be 25 a day.
Also I recall yesterday when twice clue came out within 15 minutes of each other
Random times is dumb - sound psychology shows that random rewards makes the behavior stronger. So here we sit... we are not listing nor are we bidding - just sitting. Ebay will lose their wallets with this plan. Every hour on the hour keeps ppl on ebay but still running their ususal business.