Potentially. A full sleep cycle is approximately ninety minutes in length. If you wake in the middle of the cycle, you take a cognitive performance hit for the rest of the day. So, in some cases, sleeping for thirty fewer minutes can lead to higher subsequent alertness. This is a crucial consideration when you're only allowed to get a few hours of sleep at a time.

Case in point: I've known a number of individuals with highly variable sleep schedules imposed by their work who performed this calculation manually. I imagine that they would find an application or a cycle-aware alarm clock on their phones to be quite handy.

Aside from that, calling someone's work the "dumbest thing you've ever seen" is both unnecessary and probably untrue. Please don't be uncivil.

I say call a spade a spade. This is dumb and perhaps only useful to obsessive compulsive individuals who feel some need to micromanage every aspect of their life.