If you’ve worked with calendars, then you know the frustration of having two systems not keep events in sync. There are essentially three levels to keeping events in sync. The first is integration with every email provider you wish to support. Not a light initiative. The second is to find a product which aggregates multiple providers into a single API interface. Better solution, but open your wallet. Lastly, build a lightweight system that relies on the iCalendar standard. This last option is the focus of the article. Throughout the remainder of this post, we’ll explore pushing an event to an external provider’s calendar and keeping it in sync across systems without writing a single API request or integration.