Plone 5.0.4 Migration with Transmogrifer incorrect Start Date on Events

I am using collective.jsonmigrator, along with packages and transmogrify.dexterity to migrate content from Plone 4.3.7 to Plone 5.0.4. We want to start completely fresh with Plone 5 and transmogrifier pipelines are attractive in eliminating the cruft. Everything seems to work with the exception of dates on the new Event types in 5.0.4. I found that the start and end date keys in Plone 5.0.4 have been renamed (probably since 5's inception) to start and end respectively. I have scoured through all kinds of documentation trying to find a solution as to how to properly re-map the fields to the new field names in Plone 5.0.4 with little success. Can anyone please point me in the right direction on where I can find docs, or sample code on how to accomplish such a thing.

Thank you in advance!

Check the crazy Workaround in this Thread. It's not a solution for Transmogrifer, but possibly it could help to upgrade the Content.