diff --git a/app/models/event.rb b/app/models/event.rb
index 7b21ee73..388bede8 100644
--- a/app/models/event.rb
+++ b/app/models/event.rb
@@ -288,6 +288,10 @@ class Event < ApplicationRecord
     program.conference
   end
 
+  def <=>(other)
+    time <=> other.time
+  end
+
   private
 
   ##
diff --git a/app/models/program.rb b/app/models/program.rb
index 8db24c6c..48c9d361 100644
--- a/app/models/program.rb
+++ b/app/models/program.rb
@@ -20,7 +20,7 @@ class Program < ApplicationRecord
     end
 
     def with_registration_open
-      select { |e| e if e.registration_possible? }
+      select { |e| e if e.registration_possible? }.sort
     end
 
     # All confirmed events of the conference with attribute require_registration