* lisp/calendar/time-date.el (date-to-time): Drop fallback code.
Document that the default timezone is local time, rather than GMT.
* test/lisp/calendar/time-date-tests.el (test-date-to-time):
Add more test cases.
* doc/lispref/os.texi (Time Parsing): Document that 'date-to-time'
defaults to local time.
* etc/NEWS: Announce the change. (Bug#72570)