Stores and parses Experiment's start_time as a UNIX integer.

lib/split/experiment.rb

@@ -65,7 +65,7 @@ def save
 
       if new_record?
         Split.redis.sadd(:experiments, name)
-        Split.redis.hset(:experiment_start_times, @name, Time.now)
+        Split.redis.hset(:experiment_start_times, @name, Time.now.to_i)
         @alternatives.reverse.each {|a| Split.redis.lpush(name, a.name)}
         @goals.reverse.each {|a| Split.redis.lpush(goals_key, a)} unless @goals.nil?
       else
@@ -157,7 +157,14 @@ def reset_winner
 
     def start_time
       t = Split.redis.hget(:experiment_start_times, @name)
-      Time.parse(t) if t
+      if t
+        # Check if stored time is an integer
+        if t =~ /^[-+]?[0-9]+$/
+          t = Time.at(t.to_i)
+        else
+          t = Time.parse(t)
+        end
+      end
     end
 
     def next_alternative

spec/experiment_spec.rb

@@ -44,7 +44,7 @@ def alternative(color)
     end
 
     it "should save the start time to redis" do
-      experiment_start_time = Time.parse("Sat Mar 03 14:01:03")
+      experiment_start_time = Time.at(1372167761)
       Time.stub(:now => experiment_start_time)
       experiment.save
 
@@ -59,6 +59,15 @@ def alternative(color)
       Split::Experiment.find('basket_text').algorithm.should == experiment_algorithm
     end
 
+    it "should handle having a start time stored as a string" do
+      experiment_start_time = Time.parse("Sat Mar 03 14:01:03")
+      Time.stub(:now => experiment_start_time)
+      experiment.save
+      Split.redis.hset(:experiment_start_times, experiment.name, experiment_start_time)
+
+      Split::Experiment.find('basket_text').start_time.should == experiment_start_time
+    end
+
     it "should handle not having a start time" do
       experiment_start_time = Time.parse("Sat Mar 03 14:01:03")
       Time.stub(:now => experiment_start_time)