diff --git a/app/controllers/statistics_controller.rb b/app/controllers/statistics_controller.rb
index 0c60b697..8640a9cd 100644
--- a/app/controllers/statistics_controller.rb
+++ b/app/controllers/statistics_controller.rb
@@ -38,8 +38,8 @@ class StatisticsController < ApplicationController
       format.html { render 'rfc_activity_history' }
       format.json do
         interval = params[:interval] || 'year'
-        from = DateTime.strptime(params[:from], '%Y') rescue DateTime.new(0)
-        to = DateTime.strptime(params[:to], '%Y') rescue DateTime.now
+        from = DateTime.strptime(params[:from], '%Y-%M-%D') rescue DateTime.new(0)
+        to = DateTime.strptime(params[:to], '%Y-%M-%D') rescue DateTime.now
         render(json: ranged_rfc_data(interval, from, to))
       end
     end