diff --git a/README.md b/README.md
index b5381e7..8fe6d36 100644
--- a/README.md
+++ b/README.md
@@ -254,13 +254,13 @@ Here's an example response that includes conventional `X-RateLimit-*` headers:
 
 ```ruby
 Rack::Attack.throttled_response = lambda do |env|
-  now = Time.now
   match_data = env['rack.attack.match_data']
+  now = match_data[:epoch_time]
 
   headers = {
     'X-RateLimit-Limit' => match_data[:limit].to_s,
     'X-RateLimit-Remaining' => '0',
-    'X-RateLimit-Reset' => (now + (match_data[:period] - now.to_i % match_data[:period])).to_s
+    'X-RateLimit-Reset' => (now + (match_data[:period] - now % match_data[:period])).to_s
   }
 
   [ 429, headers, ["Throttled\n"]]
@@ -271,7 +271,7 @@ end
 For responses that did not exceed a throttle limit, Rack::Attack annotates the env with match data:
 
 ```ruby
-request.env['rack.attack.throttle_data'][name] # => { :count => n, :period => p, :limit => l }
+request.env['rack.attack.throttle_data'][name] # => { :count => n, :period => p, :limit => l, :epoch_time => t }
 ```
 
 ## Logging & Instrumentation
diff --git a/lib/rack/attack/cache.rb b/lib/rack/attack/cache.rb
index c2dd06c..73f0ca2 100644
--- a/lib/rack/attack/cache.rb
+++ b/lib/rack/attack/cache.rb
@@ -3,6 +3,7 @@ module Rack
     class Cache
 
       attr_accessor :prefix
+      attr_reader :last_epoch_time
 
       def initialize
         self.store = ::Rails.cache if defined?(::Rails.cache)
@@ -39,10 +40,10 @@ module Rack
       private
 
       def key_and_expiry(unprefixed_key, period)
-        epoch_time = Time.now.to_i
+        @last_epoch_time = Time.now.to_i
         # Add 1 to expires_in to avoid timing error: http://git.io/i1PHXA
-        expires_in = (period - (epoch_time % period) + 1).to_i
-        ["#{prefix}:#{(epoch_time / period).to_i}:#{unprefixed_key}", expires_in]
+        expires_in = (period - (@last_epoch_time % period) + 1).to_i
+        ["#{prefix}:#{(@last_epoch_time / period).to_i}:#{unprefixed_key}", expires_in]
       end
 
       def do_count(key, expires_in)
diff --git a/lib/rack/attack/throttle.rb b/lib/rack/attack/throttle.rb
index 19a6519..4dc999d 100644
--- a/lib/rack/attack/throttle.rb
+++ b/lib/rack/attack/throttle.rb
@@ -26,12 +26,15 @@ module Rack
         current_limit  = limit.respond_to?(:call) ? limit.call(req) : limit
         key            = "#{name}:#{discriminator}"
         count          = cache.count(key, current_period)
+        epoch_time     = cache.last_epoch_time
 
         data = {
           :count => count,
           :period => current_period,
-          :limit => current_limit
+          :limit => current_limit,
+          :epoch_time => epoch_time
         }
+
         (req.env['rack.attack.throttle_data'] ||= {})[name] = data
 
         (count > current_limit).tap do |throttled|
diff --git a/spec/rack_attack_throttle_spec.rb b/spec/rack_attack_throttle_spec.rb
index 28ab26c..5befbe9 100644
--- a/spec/rack_attack_throttle_spec.rb
+++ b/spec/rack_attack_throttle_spec.rb
@@ -20,7 +20,7 @@ describe 'Rack::Attack.throttle' do
     end
 
     it 'should populate throttle data' do
-      data = { :count => 1, :limit => 1, :period => @period }
+      data = { :count => 1, :limit => 1, :period => @period, epoch_time: Rack::Attack.cache.last_epoch_time.to_i }
       last_request.env['rack.attack.throttle_data']['ip/sec'].must_equal data
     end
   end
@@ -37,7 +37,7 @@ describe 'Rack::Attack.throttle' do
     it 'should tag the env' do
       last_request.env['rack.attack.matched'].must_equal 'ip/sec'
       last_request.env['rack.attack.match_type'].must_equal :throttle
-      last_request.env['rack.attack.match_data'].must_equal({:count => 2, :limit => 1, :period => @period})
+      last_request.env['rack.attack.match_data'].must_equal({:count => 2, :limit => 1, :period => @period, epoch_time: Rack::Attack.cache.last_epoch_time.to_i})
       last_request.env['rack.attack.match_discriminator'].must_equal('1.2.3.4')
     end
 
@@ -65,7 +65,7 @@ describe 'Rack::Attack.throttle with limit as proc' do
     end
 
     it 'should populate throttle data' do
-      data = { :count => 1, :limit => 1, :period => @period }
+      data = { :count => 1, :limit => 1, :period => @period, epoch_time: Rack::Attack.cache.last_epoch_time.to_i }
       last_request.env['rack.attack.throttle_data']['ip/sec'].must_equal data
     end
   end
@@ -89,7 +89,7 @@ describe 'Rack::Attack.throttle with period as proc' do
     end
 
     it 'should populate throttle data' do
-      data = { :count => 1, :limit => 1, :period => @period }
+      data = { :count => 1, :limit => 1, :period => @period, epoch_time: Rack::Attack.cache.last_epoch_time.to_i }
       last_request.env['rack.attack.throttle_data']['ip/sec'].must_equal data
     end
   end