diff --git a/lib/tasks/public_message.rake b/lib/tasks/public_message.rake
index 00299cabc..e51917a2e 100644
--- a/lib/tasks/public_message.rake
+++ b/lib/tasks/public_message.rake
@@ -1,4 +1,4 @@
-# bundle exec rake sync:public_message args=149,2903
+# RAILS_ENV=production bundle exec rake sync:sigle_message args=3,-1,8848,48337,'2017-07-23','2017-10-31',1000
 namespace :sync do
   if ENV['args']
     subject_id = ENV['args'].split(",")[0] # 对应课程的id
@@ -33,7 +33,7 @@ namespace :sync do
     else
       shixun_ids = Shixun.find_by_sql("select shixun_id from stage_shixuns where stage_id in (select id from stages where
                                        subject_id=#{subject_id}) ").map(&:shixun_id)
-      discusses = Discuss.where("parent_id is null").where(dis_id: shixun_ids)
+      discusses = Discuss.where("parent_id is null and created_at between '#{start_time}' and '#{end_time}'").where(dis_id: shixun_ids)
     end
 
     discusses.each do |discuss|