Take a look at this code. I know it is a different system but a lot of similarities.
https://wordpress.org/plugins/events-made-easy/
Ron
There was a third party app that did this when facebook did an api update the author did a few tweaks and then basically abandoned it. If you send me an email I will send you some code to look out. Maybe it will help.
ron
info at broadleafpost period com
Plug in WP to Twitter has built in integration for plugin events manager. I am trying to figure out the proper syntax for a tweet
