A free program for Android, by mycolorscreen.
Zooper Widget is an extremely customizable widget that allows you to change almost everything, from colors and backgrounds to texts and icons. It can be configured to look like an analog clock, a date, a weather forecast, a compass, a map, or anything else you can think of.
It will not only display the current time and date but will also notify you of any changes that may have occurred. If there is any change in the current time or date, the app will also notify you of that fact.
If you have a certain event that you want to be notified of, you can specify the time and date for that event. Zooper Widget will then notify you of that event.