Can iCloud Keep Notes in Sync While a Note being updated?

I just started to use iCloud to keep the notes on my iMac and iPad mini/iPod touch in sync. After finished the setup all my notes under iCloud worked

well. Three devices have the same sets of notes.

However, when I did some editing of a note on iMac, added more texts. After 5 hours I noticed the note on my iPad mini was not updated at all.

I tried to find any button to manually do a iCloud sync, found nothing for users to activate sync process.

Any one had such experience? Is iCloud sync not smart enough to tell creation time for each note or some thing is wrong with my setting. I don't see

any user setting like how often data need to be synced with iCloud.

Thanks