That's another area where UA and AA are slightly different. AA gives you 8 systemwides when you qualify/requalify, so you could conceivably stretch those systemwides out to as much as 26 months and beyond. For instance, if you flew 100,000 miles this month, you'd immediately get systemwides good until the end of February, 2010, so 25 months of use. In reality, if you have systemwides that are expiring, AA has been allowing upgrades past the expiration date if you can get at least one segment to clear up front, so you could be stretching some of them out over 3 years.