From Ulf Jasper <ulf.jasper@web.de>:

From  Ulf Jasper  <ulf.jasper@web.de>:

(icalendar-version): Increase to 0.08.
(icalendar--split-value): Change name of work buffer.
(icalendar--get-weekday-abbrev): Return nil on error.
(icalendar--date-to-isodate): New function.
(icalendar-convert-diary-to-ical)
(icalendar-extract-ical-from-buffer): Use only two args for
make-obsolete (XEmacs compatibility).
(icalendar-export-file, icalendar-import-file): Blank at end of prompt.
(icalendar-export-region): Doc fix.  If error, return non-nil
and write errors to buffer ` *icalendar-errors*'.  Use correct weekday
for weekly recurring events.  Check whether date has been parsed for
ordinary events.  Make weekly events start in the year 2000.  DTEND is
non-inclusive, shift end date by one day if necessary (not for entries
that have date and time).  Rename local let variables: oops ->
found-error, datestring -> startdatestring.