Ares might be different then my LMT but when you purchase the tickets you request the date they are for. I put in the actual date of when I plan to use the tickets and not the day before when I actually arrive. Now my voucher says in big bold letters that its service date is for the day of and expires 60 days after that. I figure that means I can't reddem them the night before when I arrive. Stupid, stupid, stupid...
Totally kicking myself.
FYI, LMT is cheaper than Ares if you are planning on staying more than 3 days. You just might have to request they refund you for a foreign exchange fee.