Clock is designed to help you keep track of the time and remind yourself of things like appointments during the day.
Clock shows you the time in a big, easy-to-read font, and you can make it speak aloud the time. You can set it to chime every quarter, half or on the hour, or simply refer to it when you like.
You can add Reminders to Clock so that at a particular time every day your message is displayed in a large font and an alert sounds until you dismiss it. This helps you keep track of things you want to do during the day, so it is deliberately hard to miss.
Advanced users can hide it to the system tray (notification area) so that it is out of the way when you are concentrating on something else.