As we know this kanji means "divide / part / minute / understand" and many other meanings but these are the main meanings .. and I can understand the first two because they are related to the etymology of the kanji but I can't understand the meanings "minute" and "understand"...
I read before something like "because it meant part and minute is part of the hour it also meant minute", but I think this is not a clear explanation, because for example second is a part of the minute and the hour is a part of the day so why does this kanji especially mean 'minute'?
And for the last meaning I didn't find any explanation .. how does this kanji mean "understand"?