Update UNTIL handling. iCal exports an UNTIL that is sometimes

on the day after the event.  My guess is that it stores the UNTIL
internally as 23:59:59 on the last day of the event, and timezone
conversion sometimes changes this to the next day.

Luckily, it's possible to recognize this, because iCal uses an illegal
UNTIL format for these anyway -- RFC 2445 says that an UNTIL with a
time MUST be in UTC, and these are not.  Therefore, if an event has
an UNTIL with a time that's not in UTC, and the time is before noon,
subtract a day.  Events with UNTIL= values that comply to the RFC are
not modified by this heuristic.

1 files changed, 15 insertions, 2 deletions

diff --git a/functions/ical_parser.php b/functions/ical_parser.php
index 71ecb2f..d385b0e 100644
--- a/functions/ical_parser.php
+++ b/functions/ical_parser.php
@@ -192,13 +192,26 @@ if ($parse_file) {
 							break;
 						case 'UNTIL':
 							$until = ereg_replace('T', '', $val);
-							$until = ereg_replace('Z', '', $val);
+							$until = ereg_replace('Z', '', $until);
 							ereg ('([0-9]{4})([0-9]{2})([0-9]{2})([0-9]{0,2})([0-9]{0,2})', $until, $regs);
 							$year = $regs[1];
 							$month = $regs[2];
 							$day = $regs[3];
 							$until = mktime(0,0,0,$month,$day,$year);
-							$until = strtotime('-1 day', $until);
+							if (ereg('^([0-9]{4})([0-9]{2})([0-9]{2})T([0-9]{2})([0-9]{2})([0-9]{2})$', $val)) {
+								// RFC 2445 says that if an UNTIL has a date-time value,
+								// it MUST be in UTC (i.e. trailing Z).  iCal tends to
+								// put an end date on the next day early in the morning,
+								// not in UTC time, so we try to correct for it.
+								//
+								// Bill's guess: iCal stores the UNTIL internally as
+								// 23:59:59 UTC, then accidentally converts that to local
+								// time when exporting the event.  Thus, if the UNTIL time
+								// is before noon, it is a day ahead; if it's after noon
+								// it's the right day.
+								if ($regs[4] < 12)
+									$until = strtotime('-1 day', $until);
+							}
 							break;
 						case 'INTERVAL':
 							$number = $val;