Allow the specification of an offset (using :at => [1-59]) when using

every( X.minutes ) { ... } for job definition. For example:

 every 5.minutes, :at => 1 do
          command "blahblah"
 end

produces

 1,6,11,16,21,26,31,36,41,46,51,56 * * * * blahblah

lib/whenever/outputs/cron.rb

@@ -77,7 +77,7 @@ module Whenever
             raise ArgumentError, "Time must be in minutes or higher"
           when 1.minute...1.hour
             minute_frequency = @time / 60
-            timing[0] = comma_separated_timing(minute_frequency, 59)
+            timing[0] = comma_separated_timing(minute_frequency, 59, @at || 0)
           when 1.hour...1.day
             hour_frequency = (@time / 60 / 60).round
             timing[0] = @at.is_a?(Time) ? @at.min : @at

test/output_at_test.rb

@@ -175,4 +175,63 @@ class OutputAtTest < Test::Unit::TestCase
     end
   end
   
+  context "every 5 minutes but but starting at 1" do
+    setup do
+      @output = Whenever.cron \
+      <<-file
+        every 5.minutes, :at => 1 do
+          command "blahblah"
+        end
+      file
+    end
+    
+    should "output the command using that time" do
+      assert_match '1,6,11,16,21,26,31,36,41,46,51,56 * * * * blahblah', @output
+    end
+  end
+
+  context "every 4 minutes but starting at 2" do
+    setup do
+      @output = Whenever.cron \
+      <<-file
+        every 4.minutes, :at => 2 do
+          command "blahblah"
+        end
+      file
+    end
+    
+    should "output the command using that time" do
+      assert_match '2,6,10,14,18,22,26,30,34,38,42,46,50,54,58 * * * * blahblah', @output
+    end
+  end
+
+  context "every 3 minutes but starting at 7" do
+    setup do
+      @output = Whenever.cron \
+      <<-file
+        every 3.minutes, :at => 7 do
+          command "blahblah"
+        end
+      file
+    end
+    
+    should "output the command using that time" do
+      assert_match '7,10,13,16,19,22,25,28,31,34,37,40,43,46,49,52,55,58 * * * * blahblah', @output
+    end
+  end
+
+  context "every 2 minutes but starting at 27" do
+    setup do
+      @output = Whenever.cron \
+      <<-file
+        every 2.minutes, :at => 27 do
+          command "blahblah"
+        end
+      file
+    end
+    
+    should "output the command using that time" do
+      assert_match '27,29,31,33,35,37,39,41,43,45,47,49,51,53,55,57,59 * * * * blahblah', @output
+    end
+  end
 end