When I go to vegas, I like to wake up late around 3pm, eat lunch do all the sight seeing have dinner, then start max betting away around 10pm. I like playing when it is still crowded just to see what machines has been hitting but late enough so the crowd will start to die down and more machines open up. I doubt machines know what time it is and when to start paying out, but when a lot of people are playing at the same time you see a lot of play hence more jackpots. It depends on when you like to play.

If I can give you one word of advice, if you care about your player rating:
Find out what the casino considers as a "gaming day." Some considers a gaming day to be Midnight to Midnight. Others consider it to be 6am to 6am. Why does this matter? Casinos base your play on how much you gamble on each trip and this can impact the offers you receive. For instance if you gamble and earn "1000" slot points in one day you will earn Y offers. But if you earn 1000 points over 2 days instead of 1 day, your average will be lowered and you might not receive as many valuable offers. So I would advise you to play as much in one "gaming day" to increase your average and you might notice better offers. Just a lil tid bit I wanted to share.

TOP DOLLAR PLAYER