diff --git a/bin/git_stats b/bin/git_stats
index 36db0405e..8311ddbc1 100755
--- a/bin/git_stats
+++ b/bin/git_stats
@@ -7,9 +7,5 @@ $LOAD_PATH.unshift(lib) if File.directory?(lib) && !$LOAD_PATH.include?(lib)
 # start up the CLI
 require "git_stats/cli"
 
-begin
-  cli = GitStats::CLI.new
-  cli.start(*ARGV)
-rescue ArgumentError => e
-  puts e.message
-end
\ No newline at end of file
+cli = GitStats::CLI.new
+cli.start(*ARGV)
diff --git a/lib/git_stats/git_data/activity.rb b/lib/git_stats/git_data/activity.rb
index 1704400a2..77fc78589 100644
--- a/lib/git_stats/git_data/activity.rb
+++ b/lib/git_stats/git_data/activity.rb
@@ -5,15 +5,37 @@ module GitStats
       attr_reader :by_hour, :by_wday, :by_wday_hour, :by_month, :by_year, :by_year_week
 
       def initialize(commits)
-        @by_hour = @by_wday = @by_month = @by_year = Hash.new(0)
-        @by_wday_hour = @by_year_week = Hash.new { |h, k| h[k] = Hash.new(0) }
-
         add_commits(commits)
       end
 
+      def by_hour
+        @by_hour ||= default_hash
+      end
+
+      def by_wday
+        @by_wday ||= default_hash
+      end
+
+      def by_wday_hour
+        @by_wday_hour ||= default_double_hash
+      end
+
+      def by_month
+        @by_month ||= default_hash
+      end
+
+      def by_year
+        @by_year ||= default_hash
+      end
+
+      def by_year_month
+        @by_year_week ||= default_double_hash
+      end
+
       private
       def add_commits(commits)
-        commits.values.each do |commit|
+        commits = commits.values if commits.is_a? Hash
+        commits.each do |commit|
           add_commit_at(commit.date)
         end
       end
@@ -24,7 +46,15 @@ module GitStats
         self.by_wday_hour[date.wday][date.hour] += 1
         self.by_month[date.month] += 1
         self.by_year[date.year] += 1
-        self.by_year_week[date.year][date.cweek] += 1
+        self.by_year_month[date.year][date.month] += 1
+      end
+
+      def default_hash
+        Hash.new(0)
+      end
+
+      def default_double_hash
+        Hash.new { |h, k| h[k] = Hash.new(0) }
       end
 
     end
diff --git a/lib/git_stats/git_data/commit.rb b/lib/git_stats/git_data/commit.rb
index a76bebd31..b1cbb6074 100644
--- a/lib/git_stats/git_data/commit.rb
+++ b/lib/git_stats/git_data/commit.rb
@@ -7,11 +7,6 @@ module GitStats
 
       attr_reader :repo, :hash, :stamp, :date, :author
 
-      def gather_all_data
-        files_count
-        short_stat
-      end
-
       def files_count
         @files_count ||= Command.new(repo, "git ls-tree -r --name-only #{self.hash} | wc -l").run.to_i
       end
diff --git a/spec/activity_spec.rb b/spec/activity_spec.rb
new file mode 100644
index 000000000..4ba6baad0
--- /dev/null
+++ b/spec/activity_spec.rb
@@ -0,0 +1,37 @@
+require 'spec_helper'
+
+describe GitStats::GitData::Activity do
+  let(:dates) { [
+      '10.05.2012 12:37',
+      '10.05.2012 13:53',
+      '06.05.2012 13:23',
+      '15.06.2011 15:02',
+      '27.09.2011 15:34'
+  ] }
+  let(:commits) { dates.map { |d| double(:date => DateTime.parse(d)) } }
+  let(:activity) { GitStats::GitData::Activity.new(commits) }
+
+  it 'by_hour should count commits by hour' do
+    activity.by_hour.should == {12 => 1, 13 => 2, 15 => 2}
+  end
+
+  it 'by_wday should count commits by day of week where 0 = sunday, 1 = monday, ...' do
+    activity.by_wday.should == {0 => 1, 2 => 1, 3 => 1, 4 => 2}
+  end
+
+  it 'by_wday_hour should count commits by day of week and by hour' do
+    activity.by_wday_hour.should == {0 => {13 => 1}, 2 => {15 => 1}, 3 => {15 => 1}, 4 => {12 => 1, 13 => 1}}
+  end
+
+  it 'by_month should count commits by month' do
+    activity.by_month.should == {5 => 3, 6 => 1, 9 => 1}
+  end
+
+  it 'by_year should count commits by year' do
+    activity.by_year.should == {2011 => 2, 2012 => 3}
+  end
+
+  it 'by_year_month should count commits by day of year and by month' do
+    activity.by_year_month.should == {2011 => {6 => 1, 9 => 1}, 2012 => {5 => 3}}
+  end
+end
\ No newline at end of file