Building a calendar component requires generating grids of days, handling month navigation, and marking events on specific dates. As the creator of CoreUI with over 10 years of React experience since 2014, I’ve built calendar interfaces for booking systems, scheduling tools, and project management dashboards. The most effective approach calculates the days grid from the current month state, renders weeks as rows, and highlights today and event dates. This produces a functional calendar with pure React and no external date libraries.