From Maximus's Solutions:
Ultimate Calendar - is easy to use calendar with rich features and settings. These are its main characteristics:
Calendar for any year from 1 to 9999-th in table and list.
Common and personal dates differing by sets and groups.
Movable, recurring, periodical, particular dates.
Internal editor for easy work with dates sets.
Two view modes: Whole year and Monthly.
Popup window which contains the list of nearest events and displayed when the mouse hovers over the tray icon.
Moving weekend days.
Tracking change of day.
Options "Autostart on system startup", "Hide to tray on minimize", "Run only one copy", "Always on top".
Plugins and displaying schemes support.
Possibility to limit displaying and use priorities.
Export to Microsoft Excel and formats BMP, RTF, TXT.
Multilingual interface and Unicode support.
Contains predefined dates sets for Armenia, Austria, Belarus, Belgium, Canada, Denmark, Estonia, France, Germany, Greece, Italy, Kazakhstan, Kyrgyzstan, Macedonia, Netherlands, Norway, Russia, Serbia, Ukraine, USA.