As soon as Fred pressed the button Fred still felt tired, but in a more "I'm 6 hours into my shift, haven't taken a break yet, and just want to go home" tired instead of a sleepy kind.
His mouth said "And here's your Mint Shake!" as his hand mechanically held out a special Saint Patrick's day milkshake they had... in March... Had he gone back in time a few months? In his other hand he still felt the remote and looking down one of the words on the remote still looked like gibberish but there was a mental pressure that seemed to translate to him... Something akin to "Rewinding" or "Youthening" or "Regressing"... did he just regress time?
Samantha came up "Fred! What are you doing staring into the floor daydreaming!?! There's still-" *SMACK* went a hand against cheek again as the restaurant went quiet. Fred had ruined this job in the future, but he wanted to relish that feeling again... then he pressed the button again and rewound to Samantha yelling at him about "-ring into the floor daydreaming!?! There's still a line!" then Fred wondered what would happen if he pressed the button while- Samantha's face and form got a bit cuter as she went from middle-aged to just an adult... and a few button presses Fred grinned as she turned into a teenager as she looked at her form in baggy clothing, and then into a child, and then crying as a baby in a puddle of clothes. Fred then hit the regress button again as people started getting impatient for their food, and Fred found himself back in his apartment the previous day after his shift. He'd need to experiment, and maybe find a way to go into the future... but he could just keep undoing so much! He'd need a target though... He was lucky the time regression hadn't gone all the way to the dinosaurs or somewhere when his existence wouldn't occur for who knows how long? Now how to test this out?