Time in Neverland doesn't pass slower or faster, it doesn't pass at all, it stands still. And it is as crazy, or mind-boggling as it can get. It's pretty hard to imagine, and quite impossible to show,
Would that mean, that there is no night and day for example? Doesn't have to, and as far as we can tell from what we've seen from past and present Neverland it might not, at least in the past there was something like daylight. But present Neverland seems to be stuck in a sort of lasting twilight.
When you put people in a place cut off from outside world, they might lose after a while synchrony with the day-night rhythm of the outside world. Interestingly enough it seems though, that humans still will stay close to a 24-hour rhythm (some research says it's closer to 25-hour, but that is disputable), all that happens is, that they might after a while be so asynchronous, that they go to sleep while it's daylight in the outside world, convinced it is night. This might mess up though somewhat your perception, how much time has gone by since you're in isolation.
Something that seems to happen in isolation is, that you lose count of days, having no orientation, one day being like the other. That is, when you have no sort of time reference, no clock, no calendar. How do you know, that a week as gone by? We do so by measuring time, we use clocks and calendars to do it, which are based largely on perception of change, repetition and cycles in nature.
When time stands still in Neverland it's not just that people don't age, it has influence on how one perceives time. Clocks and calendars are something of the real world or other realms. Clocks and calendars organize time, make it count, while in Neverland time doesn't count, it stands still. It is possible that Wendy felt like a long time had gone by, while back in London it was just a night. As well it might feel for Regina like a week while in Storybook 5 days went by (although considering that 5 days are pretty much a week, aka a working week, it might be just expression and not a real difference in time, or time perception even)
Rumple and Regina looking like they've just began waiting while for Ariel it must have been at least a couple of hours, sounded like it was close to a day - well, we don't know, what Rumple and Regina did, we don't see it. Possible they were sitting around at that beach, doing nothing else than waiting for a day, just not perceiving it like a day. Or it was no day just five minutes. When you have nothing to give any sort of reference measuring time is hard or impossible.
So it is perception. And in a way fact. That kind of change in perception probably only works, when taken out of the time frame we are used to live in.
But, one can very well ask if it is not perception which creates one's reality anyway. ;)
Still confused? Don't worry, time can be a confusing matter when you start to think about it instead of taking it as a given thing. In fiction and in non-fiction.