The Time and Date Opera widget displays a calendar and a list of events/holidays for the selected day. 

The Time and Date Opera widget's Settings window allows you to change your country and language, widget's skin, alarm sound, date placement and more. 

The Time and Date Opera widget's Import and export window allows you to quickly import and export settings and/or events or import/export iCalendar files. 

The Time and Date Opera widget's Event window enables you to quickly add/remove/edit an event.