diff --git a/lib/cylc/cycling/iso8601.py b/lib/cylc/cycling/iso8601.py
index 49f2e808f42..19b58465f7e 100755
--- a/lib/cylc/cycling/iso8601.py
+++ b/lib/cylc/cycling/iso8601.py
@@ -34,7 +34,7 @@
 CYCLER_TYPE_ISO8601 = "iso8601"
 CYCLER_TYPE_SORT_KEY_ISO8601 = "b"
 
-MEMOIZE_LIMIT = 10000
+MEMOIZE_LIMIT = 100000
 
 DATE_TIME_FORMAT = "CCYYMMDDThhmm"
 EXPANDED_DATE_TIME_FORMAT = "+XCCYYMMDDThhmm"
@@ -321,7 +321,7 @@ class ISO8601Sequence(SequenceBase):
 
     TYPE = CYCLER_TYPE_ISO8601
     TYPE_SORT_KEY = CYCLER_TYPE_SORT_KEY_ISO8601
-    _MAX_CACHED_POINTS = 100
+    _MAX_CACHED_POINTS = 1000
 
     __slots__ = ('dep_section', 'context_start_point', 'context_end_point',
                  'offset', '_cached_first_point_values',
diff --git a/lib/isodatetime/data.py b/lib/isodatetime/data.py
index 539c070f570..eaecb0d3a9f 100644
--- a/lib/isodatetime/data.py
+++ b/lib/isodatetime/data.py
@@ -619,6 +619,15 @@ def copy(self):
         return TimeZone(hours=self.hours, minutes=self.minutes,
                         unknown=self.unknown)
 
+    def __cmp__(self, other):
+        if not isinstance(other, TimeZone):
+            raise TypeError(
+                "Invalid type for comparison: " +
+                "'%s' should be TimePoint." %
+                type(other).__name__
+            )
+        return cmp((self.hours, self.minutes), (other.hours, other.minutes))
+
     def __str__(self):
         if self.unknown:
             return ""
@@ -1301,8 +1310,6 @@ def __cmp__(self, other):
             raise TypeError(
                 "Cannot compare truncated to non-truncated " +
                 "TimePoint: %s, %s" % (self, other))
-        if self.get_props() == other.get_props():
-            return 0
         if self.truncated:
             for attribute in self.DATA_ATTRIBUTES:
                 other_attr = getattr(other, attribute)
@@ -1310,8 +1317,9 @@ def __cmp__(self, other):
                 if other_attr != self_attr:
                     return cmp(self_attr, other_attr)
             return 0
-        other = other.copy()
-        other.set_time_zone(self.get_time_zone())
+        if other.get_time_zone() != self.get_time_zone():
+            other = other.copy()
+            other.set_time_zone(self.get_time_zone())
         if self.get_is_calendar_date():
             my_date = self.get_calendar_date()
             other_date = other.get_calendar_date()