A calendar widget is a small application or tool that displays a calendar on a website or mobile device. It allows users to view dates, schedule events, and sometimes even set reminders. Calendar widgets can be interactive, enabling users to click on dates to add or view appointments. These widgets are often customizable, allowing users to change their appearance and functionality to suit their needs. They can be integrated with other applications, such as email or task management tools, making it easier to manage time and stay organized. Popular examples include widgets from Google Calendar and Apple Calendar.