diff --git a/app/controllers/projects_controller.rb b/app/controllers/projects_controller.rb
index 7cf068cd5..cfd032e5e 100644
--- a/app/controllers/projects_controller.rb
+++ b/app/controllers/projects_controller.rb
@@ -287,8 +287,8 @@ class ProjectsController < ApplicationController
   end
 
   def watch_users
-    start_at = params[:start_at]
-    end_at = params[:end_at]
+    start_at = params[:start_at].to_i
+    end_at = params[:end_at].to_i
     watchers = @project.watchers.includes(:user).order("watchers.created_at desc").distinct
     watchers = watchers.where("watchers.created_at > ? and watchers.created_at < ?", Time.at(start_at), Time.at(end_at)) if start_at.present? && end_at.present?
     @watchers_count = watchers.size
@@ -296,8 +296,8 @@ class ProjectsController < ApplicationController
   end
 
   def praise_users
-    start_at = params[:start_at]
-    end_at = params[:end_at]
+    start_at = params[:start_at].to_i
+    end_at = params[:end_at].to_i
     praises = @project.praise_treads.includes(:user).order("praise_treads.created_at desc").distinct
     praises = praises.where("praise_treads.created_at > ? and praise_treads.created_at < ?", Time.at(start_at), Time.at(end_at)) if start_at.present? && end_at.present?
     @praises_count = praises.size
diff --git a/app/controllers/watchers_controller.rb b/app/controllers/watchers_controller.rb
index 81ba7ceda..e6d0053a2 100644
--- a/app/controllers/watchers_controller.rb
+++ b/app/controllers/watchers_controller.rb
@@ -5,8 +5,8 @@ class WatchersController < ApplicationController
   before_action :get_target
 
   def index
-    start_at = params[:start_at]
-    end_at = params[:end_at]
+    start_at = params[:start_at].to_i
+    end_at = params[:end_at].to_i
     scope = @target.watchers.includes(:user)
     scope = scope.where("watchers.created_at > ? and watchers.created_at < ?", Time.at(start_at), Time.at(end_at)) if start_at.present? && end_at.present?
     @watchers = paginate(scope)