so, what did she do here? not really gettin it

Spent 5 hours messing with Rinnosuke in time stop or something?

No, as she said, changing other people's time is impossible for people besides the Kaguya group.

Instead, she took the simpler/mundane route - she just changed the time on the clocks while he was sleeping, so that he'd be confused about what time it was when he woke up.

When she woke him up, she claimed it was noon, but it was actually 5 am. Presumably, she did this to have an excuse to get him up and spending time with her at a time when he'd normally be asleep, and his shop closed.

Which totally doesn't disprove the idea she's a princess of the moon (see last post's comments). Even if you had that kind of power, it's got to be less effort to simply trick someone.

Not to mention more satisfying, when they realize they fell for such a simple trick.