Sync emonBase to emonCMS.org

I have emonCMS running locally on emonBase and also on emonCMS.org. My question is how to sync the data on emonBase to emonCMS after an internet outage? Will emonBase update emonCMS.org automatically with all the missing data since the last successful posting of data, or does the posting to emonCMS.org assume the internet connection is always available and therefore I would have to manually upload the data to emonCMS.org?