To integrate Google Calendar with Notion, Zapier is used to automate workflow between the two apps. By connecting these two tools, users can streamline their workday, prioritize tasks, and stay organized. With a few clicks, users can create Zaps that automatically add Google Calendar events to Notion databases, generate detailed meeting agendas, and even draft tasks based on event details. This integration enables users to make the most of both apps, enhancing productivity and efficiency in their daily routine.