diff --git a/Gemfile.lock b/Gemfile.lock
index 3e263ca..8e905de 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -5,7 +5,6 @@ PATH
       activesupport (>= 2.3.0)
       json (>= 1.4.0)
       redis (>= 2.1.0)
-      system_timer (>= 1.0.0)
       time_ext (>= 0.2.8)
 
 GEM
@@ -24,7 +23,6 @@ GEM
     rspec-expectations (2.1.0)
       diff-lcs (~> 1.1.2)
     rspec-mocks (2.1.0)
-    system_timer (1.0)
     time_ext (0.2.8)
       activesupport (>= 2.3.0)
       i18n (>= 0.4.2)
@@ -39,6 +37,5 @@ DEPENDENCIES
   redis (>= 2.1.0)
   redistat!
   rspec (>= 2.1.0)
-  system_timer (>= 1.0.0)
   time_ext (>= 0.2.8)
   yard (>= 0.6.3)
diff --git a/lib/redistat.rb b/lib/redistat.rb
index e18c076..3d26d18 100644
--- a/lib/redistat.rb
+++ b/lib/redistat.rb
@@ -26,6 +26,7 @@ require 'redistat/summary'
 require 'redistat/core_ext/date'
 require 'redistat/core_ext/time'
 require 'redistat/core_ext/fixnum'
+require 'redistat/core_ext/bignum'
 
 module Redistat
   
diff --git a/lib/redistat/core_ext/bignum.rb b/lib/redistat/core_ext/bignum.rb
new file mode 100755
index 0000000..20e08e2
--- /dev/null
+++ b/lib/redistat/core_ext/bignum.rb
@@ -0,0 +1,8 @@
+class Bignum
+  include Redistat::DateHelper
+  
+  def to_time
+    Time.at(self)
+  end
+  
+end
diff --git a/lib/redistat/date.rb b/lib/redistat/date.rb
index 48fb65e..218a914 100644
--- a/lib/redistat/date.rb
+++ b/lib/redistat/date.rb
@@ -22,6 +22,8 @@ module Redistat
         from_string(input)
       elsif input.is_a?(::Fixnum)
         from_integer(input)
+      elsif input.is_a?(::Bignum)
+        from_integer(input)
       end
     end
     
diff --git a/lib/redistat/finder/date_set.rb b/lib/redistat/finder/date_set.rb
index 32c5a60..0bb805b 100644
--- a/lib/redistat/finder/date_set.rb
+++ b/lib/redistat/finder/date_set.rb
@@ -42,7 +42,7 @@ module Redistat
         return find_start_year_for(start_date, end_date, lowest_depth) if unit == :year
         index = Date::DEPTHS.index(unit)
         nunit = Date::DEPTHS[(index > 0) ? index-1 : index]
-        if start_date < start_date.round(nunit) || start_date.next(nunit).beginning_of(nunit) > end_date.beginning_of(nunit)
+        if start_date < start_date.beginning_of_closest(nunit) || start_date.next(nunit).beginning_of(nunit) > end_date.beginning_of(nunit)
           add = []
           start_date.beginning_of_each(unit, :include_start => lowest_depth).until(start_date.end_of(nunit)) do |t|
             add << t.to_rs.to_s(unit) if t < end_date.beginning_of(unit)
@@ -59,7 +59,7 @@ module Redistat
         index = Date::DEPTHS.index(unit)
         nunit = Date::DEPTHS[(index > 0) ? index-1 : index]
         has_nunit = end_date.prev(nunit).beginning_of(nunit) >= start_date.beginning_of(nunit)
-        nearest_nunit = end_date.round(nunit)
+        nearest_nunit = end_date.beginning_of_closest(nunit)
         if end_date >= nearest_nunit && has_nunit
           add = []
           end_date.beginning_of(nunit).beginning_of_each(unit, :include_start => true, :include_end => lowest_depth).until(end_date) do |t|