I've put in 8 holiday "peak" seasons with UPS. You're contacted each morning by phone and offered a job as a "jumper" - riding (and running packages) with a regular UPS driver. You'll meet the driver at a pre-determined place and time and stay with him/her all day - or until enough of their load has been delivered. The work is hard, the weather can be tough - depending on where you live. If you're a retiree and go to exercise classes - you'll get your daily workout (and how!), and get paid well for doing so. The job gets "serious" after Thanksgiving, and you're usually done on Christmas Eve. The work is usually Monday-Friday, but your start/end times will vary depending on the UPS work load. Believe me, they're busy!
In-person training classes have been replaced by online instruction. Uniforms are no longer required. I'm looking forward to Year #9.