I was and am incredulous, but I figure I'll ask: is there any merit to the claim that you have more luck when summoning at certain times? Losing interest rapidly in this because I haven't gotten a good summon in weeks, and it seems like every day that some friend is setting his rep monster to a shiny new natural 5*. And when I test them out, they vastly outperform my 6* awakened Wind Ninja. Somebody has a level 35 FIRE Dragon that AOE'S for up to 7k against WATER monsters, whereas my WIND NINJA hits one WATER target for that amount sometimes. (Hydeni 5, hell). It could be a rune issue, but god damn this is a 5* vs a 6* monster here. These natural 5*'s appear utterly insane, and people don't seem to have issues getting them.
Edit: For example, there's a thread on Reddit that claims times x:11, x:31, x:51 yields higher chances of better monsters. I see a ton of 5*'s at these times, but that doesn't necessarily mean it works - it likely means that a lot of people are figuring "hey, why the hell not? I'll try it" and the sheer number of attempted summons at that time dramatically increases the likelihood that there'll be a success.