If the number of server requests presents a problem, then they can just have it poll the vague time once per login, and only once in a 24 hour period. It's not meant to be super precise, it's meant to prevent from having to do such a chore of taking roll and housecleaning as was mentioned before. To add to that, they can limit it only to those who are promoted in a LS and not everyone (but not just leaders, either).

I'm hoping they find some way around the limitations.