ical should be generated for next 30 days, not prev

docs/changelog/7.x.x.txt

@@ -5,6 +5,7 @@
  - fix: purging old asset revisions on large sites never completes
  - fix: Can't add assets when not using preload.perl.
  - fix: graphing doesn't work with GraphicsMagick
+ - fix: Calendar generated iCal for last 30 days instead of next 30 days
 
 7.4.8
  - fix: Syndicated Content doesn't display all items with multiple feeds in interleaved mode

lib/WebGUI/Asset/Wobject/Calendar.pm

@@ -1510,7 +1510,7 @@ sub www_ical {
         #}
         #else
         #{
-            $dt_start = WebGUI::DateTime->new($self->session, time-60*60*24*30)->set_time_zone($session->user->profileField("timeZone"));
+            $dt_start = WebGUI::DateTime->new($self->session, time)->set_time_zone($session->user->profileField("timeZone"));
         #}
     }
     else {