diff --git a/bin/git-timecost b/bin/git-timecost
index 1258eff..5319863 100755
--- a/bin/git-timecost
+++ b/bin/git-timecost
@@ -6,7 +6,6 @@ require 'date'
 require 'optparse'
 require 'yaml'
 
-$:.insert 0, 'lib'
 require 'timecost'
 
 app = TimeCost::CLI.new
diff --git a/lib/timecost/cli.rb b/lib/timecost/cli.rb
index fad7298..6a8b28b 100644
--- a/lib/timecost/cli.rb
+++ b/lib/timecost/cli.rb
@@ -95,7 +95,7 @@ module TimeCost
 					id = $1
 					# merge ranges & push
 					unless commit.nil? then
-						range = Range.new @config, commit
+						range = Range.new commit, granularity: @config[:range_granularity]
 
 						if not @rangelist.include? commit.author then
 							@rangelist[commit.author] = RangeList.new
@@ -177,7 +177,7 @@ module TimeCost
 
 			@rangelist.each do |author,rangelist|
 				rangelist.each do |range|
-					puts range.to_s + "\n"
+					puts range.to_s(!@config[:author_filter_enable]) + "\n"
 				end
 			end
 			total = 0
diff --git a/lib/timecost/range.rb b/lib/timecost/range.rb
index 627d69f..ed0f11e 100644
--- a/lib/timecost/range.rb
+++ b/lib/timecost/range.rb
@@ -3,15 +3,17 @@ module TimeCost
 	class Range
 		attr_accessor :time_start, :time_stop, :commits, :author
 
-		def initialize config, commit
-			@config = config
+		GRANULARITY_DEFAULT = 0.5
+
+		def initialize commit, options = {}
+			@granularity = options[:granularity] || GRANULARITY_DEFAULT
 
 			# FIXME: First approximation for users
 			# later, we'll replace with @user = User.parse(commit.author)
 			@author = commit.author
 
 			@time_stop = DateTime.parse(commit.date)
-			@time_start = @time_stop - (@config[:range_granularity] * 3 / 24.0)
+			@time_start = @time_stop - (@granularity * 3 / 24.0)
 			@commits = [commit]
 			self
 		end
@@ -89,16 +91,16 @@ module TimeCost
 		end
 
 		def fixed_start 
-			return @time_start + (@config[:range_granularity]/24.0)
+			return @time_start + (@granularity/24.0)
 		end
 
 		def diff 
 			return ("%.2f" % ((@time_stop - fixed_start).to_f * 24)).to_f
 		end
 
-		def to_s 
+		def to_s show_authors = true
 			val = "(%s)\t%s - %s\n" % [diff, fixed_start, @time_stop]	
-			unless @config[:author_filter_enable] then
+			if show_authors  then
 				val += "\tby %s\n" % @commits.first.author
 			end
 			@commits.each do |commit|
diff --git a/spec/cli_spec.rb b/spec/cli_spec.rb
new file mode 100644
index 0000000..6e15f64
--- /dev/null
+++ b/spec/cli_spec.rb
@@ -0,0 +1,16 @@
+
+
+require_relative 'spec_helper'
+
+require 'timecost/cli'
+
+describe TimeCost::CLI do
+	let(:cli) { TimeCost::CLI.new }
+
+	describe '.new' do
+		it "can be created without arguments" do
+			assert_instance_of TimeCost::CLI, cli
+		end
+	end
+
+end
diff --git a/spec/range_list_spec.rb b/spec/range_list_spec.rb
index e69de29..20e83b5 100644
--- a/spec/range_list_spec.rb
+++ b/spec/range_list_spec.rb
@@ -0,0 +1,26 @@
+
+require_relative 'spec_helper'
+
+require 'timecost/range_list'
+
+describe TimeCost::RangeList do
+	let(:list) { TimeCost::RangeList.new }
+
+	describe '.new' do
+		it "can be created without arguments" do
+			assert_instance_of TimeCost::RangeList, list
+		end
+	end
+
+	it "is empty at start" do
+	end
+
+	it "can insert ranges" do
+	end
+
+	it "can merge overlapping ranges" do
+	end
+
+	it "cumulates non-overlapping ranges" do
+	end
+end
diff --git a/spec/range_spec.rb b/spec/range_spec.rb
index e69de29..17fba79 100644
--- a/spec/range_spec.rb
+++ b/spec/range_spec.rb
@@ -0,0 +1,35 @@
+
+require_relative 'spec_helper'
+
+require 'timecost/range'
+
+describe TimeCost::Range do
+	let(:config) do { granularity: 0.5 } end
+
+	let(:commitA) { nil }
+	let(:commitB) { nil }
+	let(:commitC) { nil }
+	let(:commitD) { nil }
+
+	let(:rangeA) { 
+		TimeCost::Range.new commitA, config 
+	}
+
+	describe '.new' do
+		it "can be created from " do
+			assert_instance_of TimeCost::Range, rangeA
+		end
+	end
+
+	describe '.overlap?' do
+		it "must respond to .overlap?" do
+		end
+
+		it "must return false when ranges are not overlapping" do
+		end
+
+		it "must return true when ranges are overlapping" do
+		end
+	end
+end
+