well the amount of days used to stop at 255 until about a month or 2 ago. meaning that if a guy started the season @ 1.171, he'd end the season at 1.255 even if he spent the entire season in the majors. At the flip of the new season, he's be at 2.83 (255-172) and you'd move forward. W/ the new switch, he'd be at 1.347, and theortetically would start the next season at 3.003 like you mention. However, I think the change is so new, that anyone knows for sure. If you bring a guy up after 20 minor league days, the change will effect you going from season 4 to season 5, at which point he'll have 6 seasons of service, and will hit the FA market w/o the last arbitration period. However, I don't know if the sim would allow that or not, it may give the 3rd arbitration season anyways. I'm playing it safe, and holding guys back 25 days now, until its figured out how the change in counting days beyond 255 effects things.
Hope that makes sense.