diff --git a/lib/sidekiq/worker.rb b/lib/sidekiq/worker.rb
index e41de0f47..1c54efb5a 100644
--- a/lib/sidekiq/worker.rb
+++ b/lib/sidekiq/worker.rb
@@ -42,13 +42,13 @@ def perform_async(*args)
 
       def perform_in(interval, *args)
         int = interval.to_f
-        now = Time.now.to_f
-        ts = (int < 1_000_000_000 ? now + int : int)
+        now = Time.now
+        ts = (int < 1_000_000_000 ? (now + interval).to_f : int)
 
         item = { 'class' => self, 'args' => args, 'at' => ts }
 
         # Optimization to enqueue something now that is scheduled to go out now or in the past
-        item.delete('at'.freeze) if ts <= now
+        item.delete('at'.freeze) if ts <= now.to_f
 
         client_push(item)
       end
diff --git a/test/test_scheduling.rb b/test/test_scheduling.rb
index 80f610db8..c2f8757f2 100644
--- a/test/test_scheduling.rb
+++ b/test/test_scheduling.rb
@@ -30,6 +30,15 @@ def perform(x)
       @redis.verify
     end
 
+    it 'schedules a job in one month' do
+      @redis.expect :zadd, true do |key, args|
+        assert_equal 'schedule', key
+        assert_in_delta 1.month.since.to_f, args[0][0].to_f, 1
+      end
+      assert ScheduledWorker.perform_in(1.month, 'mike')
+      @redis.verify
+    end
+
     it 'schedules a job via timestamp' do
       @redis.expect :zadd, true, ['schedule', Array]
       assert ScheduledWorker.perform_in(5.days.from_now, 'mike')