FedEx=4 years
UPS=9
SWA=5-6
Cathay=Depends

Keep in mind that these are the average times for those upgrading now. The gap from 9/11 until fairly recently will skew the upgrade times for the recent new hires. Also, I can speak for UPS only, but many folks bypass the upgrade for QOL. AT UPS you can work as little as 2 days a month by bidding reserve. Many guys have side businesses and do that. At Cathay I have heard that they base their upgrades on merit. That sounds good until you are bypassed because someone in Hon Kong decides you are not worthy. Almost all US carriers base upgrades on seniority order of when you were hired.