Do Orbitz ticket vouchers ever expire if not used?

[SuzyQue]

Already posted this on Budget board with no response. I know they expire 14 days after first use, but what if you don't use them for another year or so? They ask for your dates before they give prices, but I can't find anywhere on their site if the voucher is only good for the dates you entered. We are booked through Disney and only buying tickets through Orbitz which have a better price on their 5-day hopper than Undercover Tourist. TIA