As a product manager, my first step in designing a calendar product for Facebook would be to conduct extensive user research to better understand the needs and preferences of Facebook users. This would include gathering data on how users currently manage their schedules, what features and functionality they are looking for in a calendar tool, and how often they use social media platforms like Facebook. Based on this user research, I would work with a team of designers and developers to create a calendar product that is intuitive, user-friendly, and integrates seamlessly with other Facebook features. Some potential features that we might consider include the ability to schedule Facebook events directly from the calendar, view friends' birthdays and other important dates, and receive notifications when events are coming up. In addition to these core features, we would also need to consider issues related to privacy and security. For example, we would want to ensure that users have control over who can see their calendar events and that their personal information is kept secure. Overall, my goal as a product manager would be to create a calendar product for Facebook that is both innovative and user-centric, providing users with a powerful tool for managing their schedules while also protecting their privacy and security.