@Brook *******
That’s fine if you don’t need one to also apply for your visa. If you do, you’re going to need a ticket rental that’s longer than just a day.
When I said I doubt your airline to Thailand would check the validity of your outgoing ticket I didn’t mean they wouldn’t check that you have one, only that I doubt they would try and log into the airline’s site with your booking to verify fits a legitimate ticket.
So you could get a ticket rental for your visa application then show it to the airline after it’s expired.