diff --git a/ChangeLog b/ChangeLog
index 4a9d1b46d..62509d775 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2011-03-23  Francis Lachapelle  <flachapelle@inverse.ca>
+
+	* UI/PreferencesUI/UIxPreferences.m (-timeZonesList): we make use
+	of the new method [iCalTimeZone knownTimeZoneNames] instead of
+	[NSTimeZone knownTimeZoneNames] to avoid listing tons of useless timezones.
+
 2011-03-22  Wolfgang Sourdeau  <wsourdeau@inverse.ca>
 
 	* OpenChange/MAPIStoreCalendarMessage.m (-init): new method to
diff --git a/SOPE/NGCards/ChangeLog b/SOPE/NGCards/ChangeLog
index 97549f4ab..156882b82 100644
--- a/SOPE/NGCards/ChangeLog
+++ b/SOPE/NGCards/ChangeLog
@@ -1,9 +1,15 @@
+2011-03-23  francis  <flachapelle@inverse.ca>
+
 2011-03-23  Francis Lachapelle  <flachapelle@inverse.ca>
 
 	* iCalRepeatableEntityObject.m (-removeAllExceptionDates): don't
 	use the method "exceptionDates" since it returns an array of
 	strings and not CardElement instances.
 
+	* iCalTimeZone.m (+knownTimeZoneNames): new class method to
+	retrieve the timezone names. Used in replacement of the same
+	method in NSTimeZone.
+
 2011-03-22  Wolfgang Sourdeau  <wsourdeau@inverse.ca>
 
 	* iCalEvent.m (-firstRecurrenceStartDate): new method that makes
diff --git a/SOPE/NGCards/iCalTimeZone.h b/SOPE/NGCards/iCalTimeZone.h
index a44bddbee..150377e87 100644
--- a/SOPE/NGCards/iCalTimeZone.h
+++ b/SOPE/NGCards/iCalTimeZone.h
@@ -33,6 +33,7 @@
 @interface iCalTimeZone : CardGroup
 
 + (iCalTimeZone *) timeZoneForName: (NSString *) theName;
++ (NSArray *) knownTimeZoneNames;
 - (NSString *) tzId;
 - (iCalTimeZonePeriod *) periodForDate: (NSCalendarDate *) date;
 - (NSCalendarDate *) computedDateForDate: (NSCalendarDate *) theDate;
diff --git a/SOPE/NGCards/iCalTimeZone.m b/SOPE/NGCards/iCalTimeZone.m
index 156110f63..310983c94 100644
--- a/SOPE/NGCards/iCalTimeZone.m
+++ b/SOPE/NGCards/iCalTimeZone.m
@@ -41,6 +41,7 @@
 #import "iCalTimeZone.h"
 
 static NSMutableDictionary *cache;
+static NSArray *knownTimeZones;
 
 
 @implementation iCalTimeZone
@@ -106,6 +107,62 @@ static NSMutableDictionary *cache;
   return o;
 }
 
+/**
+ * Fetch the names of the available timezones for which we have a
+ * vTimeZone definition (.ics).
+ * @return an array of timezones names.
+ * @see [NSTimeZone knownTimeZoneNames]
+ */
++ (NSArray *) knownTimeZoneNames
+{
+  NSFileManager *fm;
+  NSEnumerator *e;
+  NSDirectoryEnumerator *zones;
+  NSArray *paths;
+  NSMutableArray *timeZoneNames;
+  NSString *path, *zone, *zonePath;
+  NSRange ext;
+  BOOL b;
+
+  timeZoneNames = knownTimeZones;
+
+  if (!timeZoneNames)
+    {
+      timeZoneNames = [NSMutableArray new];
+
+      paths = NSSearchPathForDirectoriesInDomains(NSAllLibrariesDirectory,
+						  NSAllDomainsMask,
+						  YES);
+      fm = [NSFileManager defaultManager];
+      
+      if ([paths count] > 0)
+	{
+	  e = [paths objectEnumerator];
+	  while ((path = [e nextObject]))
+	    {
+	      path = [NSString stringWithFormat: @"%@/Libraries/Resources/NGCards/TimeZones", path];
+	      if ([fm fileExistsAtPath: path isDirectory: &b] && b)
+		{
+		  zones = [fm enumeratorAtPath: path];
+		  while ((zone = [zones nextObject])) {
+		    zonePath = [NSString stringWithFormat: @"%@/%@", path, zone];
+		    if ([fm fileExistsAtPath: zonePath isDirectory: &b] && !b)
+		      {
+			ext = [zone rangeOfString: @".ics"];
+			zone = [zone substringToIndex: ext.location];
+			[timeZoneNames addObject: zone];
+		      }
+		  }
+		}
+	    }
+	}
+      knownTimeZones = [timeZoneNames sortedArrayUsingSelector: @selector (localizedCaseInsensitiveCompare:)];
+      [knownTimeZones retain];
+    }
+
+  return timeZoneNames;
+}
+
 - (Class) classForTag: (NSString *) classTag
 {
   Class tagClass;
diff --git a/UI/PreferencesUI/UIxPreferences.m b/UI/PreferencesUI/UIxPreferences.m
index dadf9792e..685c44785 100644
--- a/UI/PreferencesUI/UIxPreferences.m
+++ b/UI/PreferencesUI/UIxPreferences.m
@@ -32,6 +32,8 @@
 
 #import <NGExtensions/NSObject+Logs.h>
 
+#import <NGCards/iCalTimeZone.h>
+
 #import <SOGo/NSArray+Utilities.h>
 #import <SOGo/NSDictionary+Utilities.h>
 #import <SOGo/NSString+Utilities.h>
@@ -149,8 +151,7 @@
 
 - (NSArray *) timeZonesList
 {
-  return [[NSTimeZone knownTimeZoneNames]
-           sortedArrayUsingSelector: @selector (localizedCaseInsensitiveCompare:)];
+  return [iCalTimeZone knownTimeZoneNames];
 }
 
 - (NSString *) userTimeZone