It doesn't matter, becasue timing doesn't sway, so if your attempt is 8 hours before O or 48 hours before O, it's irrelevant. You just need to be in with an attempt when you have a snowball's chance in heck at conception, which is not a cutoff and not O+12 or even on O day. Being in with attempt prior to ovulation but not too much prior, is best odds of conception.