There are a lot of varying opinions on this, so you might get a wide range of answers to this question.

There's been a long-standing belief that the first three matches you make on RO are going to give you the best results. I was always skeptical of this, however I did tend to have better luck with the first few matches. That being said, if I pick my best horses to breed first, of course I'm going to have the best luck with those. So I choose to take that myth with a grain of salt.

I've also noticed that the latest changes to the breeding algorithm have really helped to randomize foal results. Higher rated foals are being bred more often and not all are bred on RO.

So, I would say that timing really doesn't matter when it comes to matches. The only reason to breed earlier in the month is to have more time to train the foals up before they reach breeding age.

I've had great luck with my first 3 matches ... I've also had my first 3 matches flop, and then bred a WWW as my 7th or 8th match. But just like Cloud pointed out, I always do the matches I'm most excited about first, and those are typically my strongest, so I would expect those results to be the best.

I'm in the US and RO is at 1am for me. I don't stay up. Sometimes I can't breed until the 4th or later of the month, and I still get nice babies/WWW from my top matches.

There is always a major luck factor involved; every breeding is a roll of the dice, just like in real life. There's still the possibility of getting a surprise EWW/WWW on your last breeding, but it doesn't hurt to put your fave matches first, just in case!