I've asked several SFO AAgents very nicely before if I could try to "same day standby" for the redeye flights (usually leave a few minutes after midnight) and have always politely been told that it's considered next day. (Which it totally is - certainly not denying that. But every once in a while I toe the line just to see if they're willing to bend the rules a little. It does seem like AA's computer systems are savvy enough to recognize that Day (X) != Day (X+1). )