Originally Posted by
restlessinRNO
In other words, you cannot just appear at the NH BKK counter for the 00.30 am flight and ask to stand-by for that flight. You must contact UA and ask to change your award ticket.

Well, one can ask ANA - but they are under no obligation to put the requesting passenger onto an earlier flight. There are very likely charges for doing s

. A better approach would be to first call and ask UA to change the ticket.