-(defcustom org-icalendar-use-UTC-date-time ()
- "Non-nil force the use of the universal time for iCalendar DATE-TIME.
-The iCalendar DATE-TIME can be expressed with local time or universal Time,
-universal time could be more compatible with some external tools."
+;; Backward compatibility with previous variable
+(defvar org-icalendar-use-UTC-date-time nil)
+(defcustom org-icalendar-date-time-format
+ (if org-icalendar-use-UTC-date-time
+ ":%Y%m%dT%H%M%SZ"
+ ":%Y%m%dT%H%M%S")
+ "Format-string for exporting icalendar DATE-TIME.
+See `format-time-string' for a full documentation. The only
+difference is that `org-icalendar-timezone' is used for %Z.
+
+Interesting value are:
+ - \":%Y%m%dT%H%M%S\" for local time
+ - \";TZID=%Z:%Y%m%dT%H%M%S\" for local time with explicit timezone
+ - \":%Y%m%dT%H%M%SZ\" for time expressed in Universal Time"
+