So why, when a user books a hotel, does that information not just appear automatically in the user’s calendar? Because calendars are an integration nightmare.
Cronofy has dealt with all the complexity of integrating, maintaining and monitoring activity across the major calendar service providers. Information can be provided when customers need it, at the time they need it and in the place they need it. That means developers can interact with their customers’ calendars, no matter which calendar service they have chosen or had forced on them.
The Google Calendar API is the most sensible to integrate with. Developing and maintaining one integration point is challenging enough. Integrating with all the calendar APIs makes most potential benefits uneconomic, so there is no choice but to use ICS files and complex user instructions.