diff --git a/lib/ice_cube/schedule.rb b/lib/ice_cube/schedule.rb
index a4176926..d23de964 100644
--- a/lib/ice_cube/schedule.rb
+++ b/lib/ice_cube/schedule.rb
@@ -182,16 +182,20 @@ def occurrences_between(begin_time, closing_time)
       find_occurrences(begin_time, closing_time)
     end
 
-    # Return a boolean indicating if an occurrence falls between
-    # two times
+    # Return a boolean indicating if an occurrence falls between two times
     def occurs_between?(begin_time, closing_time)
       !find_occurrences(begin_time, closing_time, 1).empty?
     end
 
-    # Return a boolean indicating if an occurrence is occurring between
-    # two times, inclusive
-    def occurring_between?(begin_time, closing_time)
-      occurs_between?(begin_time - duration + 1, closing_time + duration - 1)
+    # Return a boolean indicating if an occurrence is occurring between two
+    # times, inclusive of its duration. This counts zero-length occurrences
+    # that intersect the start of the range and within the range, but not
+    # occurrences at the end of the range since none of their duration
+    # intersects the range.
+    def occurring_between?(opening_time, closing_time)
+      opening_time = opening_time - duration
+      closing_time = closing_time - 1 if duration > 0
+      occurs_between?(opening_time, closing_time)
     end
 
     # Return a boolean indicating if an occurrence falls on a certain date
diff --git a/spec/examples/recur_spec.rb b/spec/examples/recur_spec.rb
index ce89504e..38480bc7 100644
--- a/spec/examples/recur_spec.rb
+++ b/spec/examples/recur_spec.rb
@@ -24,34 +24,50 @@
 describe :occurring_between? do
 
   let(:start_time) { Time.local(2012, 7, 7, 7) }
+  let(:end_time)   { start_time + 30 }
+
   let(:schedule) do
     IceCube::Schedule.new(start_time, :duration => 30).tap do |schedule|
       schedule.rrule IceCube::Rule.daily
     end
   end
 
-  it 'should occur when the range is entirely contained' do
-    schedule.occurring_between?(start_time + 1, start_time + 20).should be_true
+  it 'should affirm an occurrence that spans the range exactly' do
+    schedule.occurring_between?(start_time, end_time).should be_true
+  end
+
+  it 'should affirm a zero-length occurrence at the start of the range' do
+    schedule.duration = 0
+    schedule.occurring_between?(start_time, start_time).should be_true
+  end
+
+  it 'should deny a zero-length occurrence at the end of the range' do
+    schedule.duration = 0
+    schedule.occurring_between?(end_time, end_time).should be_false
+  end
+
+  it 'should affirm an occurrence entirely contained within the range' do
+    schedule.occurring_between?(start_time + 1, end_time - 1).should be_true
   end
 
-  it 'should occur when the range is offset left' do
-    schedule.occurring_between?(start_time - 60, start_time - 29).should be_true
+  it 'should affirm an occurrence spanning across the start of the range' do
+    schedule.occurring_between?(start_time - 1, start_time + 1).should be_true
   end
 
-  it 'should occur when the range is offset right' do
-    schedule.occurring_between?(start_time + 29, start_time + 40).should be_true
+  it 'should affirm an occurrence spanning across the end of the range' do
+    schedule.occurring_between?(end_time - 1, end_time + 1).should be_true
   end
 
-  it 'should occur when the range is overflowing' do
-    schedule.occurring_between?(start_time - 29, start_time + 40).should be_true
+  it 'should affirm an occurrence spanning across the range entirely' do
+    schedule.occurring_between?(start_time - 1, end_time + 1).should be_true
   end
 
-  it 'should be false when the range starts after the duration expires' do
-    schedule.occurring_between?(start_time + 30, start_time + 40).should be_false
+  it 'should deny an occurrence before the range' do
+    schedule.occurring_between?(end_time + 1, end_time + 2).should be_false
   end
 
-  it 'should be false when the range ends before the start' do
-    schedule.occurring_between?(start_time - 40, start_time - 30).should be_false
+  it 'should deny an occurrence after the range' do
+    schedule.occurring_between?(start_time - 2, start_time - 1).should be_false
   end
 
 end