diff --git a/app/mailers/notifications_mailer.rb b/app/mailers/notifications_mailer.rb
index b57de6c..b20e4a7 100644
--- a/app/mailers/notifications_mailer.rb
+++ b/app/mailers/notifications_mailer.rb
@@ -11,19 +11,15 @@ class NotificationsMailer < ApplicationMailer
   end
 
   def domain_expires_soon
-    @expire_in_days = Integer(@check.domain_expires_at.to_date - Date.today)
-
     I18n.with_locale params&.fetch(:locale) { @check.user.locale } do
-      subject = t(".subject", domain: @check.domain, count: @expire_in_days)
+      subject = t(".subject", domain: @check.domain, count: @check.domain_expires_in_days)
       mail subject: subject, to: @notification.recipient
     end
   end
 
   def ssl_expires_soon
-    @expire_in_days = Integer(@check.domain_expires_at.to_date - Date.today)
-
     I18n.with_locale params&.fetch(:locale) { @check.user.locale } do
-      subject = t(".subject", domain: @check.domain, count: @expire_in_days)
+      subject = t(".subject", domain: @check.domain, count: @check.domain_expires_in_days)
       mail subject: subject, to: @notification.recipient
     end
   end
diff --git a/app/models/check.rb b/app/models/check.rb
index 4c744b0..c2c04b5 100644
--- a/app/models/check.rb
+++ b/app/models/check.rb
@@ -105,6 +105,10 @@ class Check < ApplicationRecord
     end
   end
 
+  def domain_expires_in_days
+    Integer(domain_expires_at.to_date - Time.now.utc.to_date)
+  end
+
   private
 
   def domain_created_at_past
diff --git a/test/models/check_test.rb b/test/models/check_test.rb
index 22fecc1..000d34e 100644
--- a/test/models/check_test.rb
+++ b/test/models/check_test.rb
@@ -123,4 +123,16 @@ class CheckTest < ActiveSupport::TestCase
     check.save!
     assert check.mode?
   end
+
+  test "expiration in days (future)" do
+    check = create(:check, domain_expires_at: 1.week.from_now)
+
+    assert_equal 7, check.domain_expires_in_days
+  end
+
+  test "expiration in days (past)" do
+    check = create(:check, domain_expires_at: 1.week.ago)
+
+    assert_equal -7, check.domain_expires_in_days
+  end
 end