/usr/share/doc/dialog/examples/calendar2 is in dialog 1.3-20171209-1.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 | #!/bin/sh
# $Id: calendar2,v 1.8 2010/01/13 10:20:03 tom Exp $
. ./setup-vars
exec 3>&1
RESULT=`$DIALOG --title "CALENDAR" "$@" --calendar "Please choose a date..." 0 0 2>&1 1>&3`
retval=$?
exec 3>&-
. ./report-string
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