Horst Schaeffer's Calendar window can be sized to display up to 12 month (any width/height ratio). The month range can be shifted step by step. Click on month or year caption to select any month or year.
Quick toggle: full year / custom layout.
The selected date (first button) or the current date and/or time (second button) can be copied to the clipboard. The date/time formats are selectable by menu (four default formats; up to 10 custom formats for each button can be assigned in the INI file).
The default date/time formats and the month/weekday names will show according to the user's regional settings.
Holidays can be defined in list(s) of annual events; emphasized dates, details on right mouse click.