widget_calendar(3tk) on Linux
The text 10fcfc023b8b, as Debian 12 (Bookworm), Debian 11 (Bullseye) shipped it.
Calendar Megawidget
Flags it lists
-
-command -
-dateformat -
-firstday -
-font -
-highlightcolor -
-language -
-shadecolor -
-showpast -
-textvariable