diff --git a/app/controllers/event_news_mods_controller.rb b/app/controllers/event_news_mods_controller.rb
index 5b34830..c699c21 100644
--- a/app/controllers/event_news_mods_controller.rb
+++ b/app/controllers/event_news_mods_controller.rb
@@ -1016,12 +1016,21 @@ class EventNewsModsController < ApplicationController
         page = Page.where(:module => "event_news_mod").first
         read_more_url_root = "/#{I18n.locale.to_s + page.url}" rescue ""
       end
-      if params[:unix_start].present? && params[:unix_end].present?
-        agenda_start = Time.at(params[:unix_start].to_i).utc.to_s
-        agenda_end = Time.at(params[:unix_end].to_i).utc.to_s
+      events = []
+      max_unix_time = 253402300799 # 對應西元 9999-12-31，超過這個範圍視為不合法輸入，避免 Time.at 收到超大整數噴 RangeError
+      unix_start = params[:unix_start].to_i
+      unix_end   = params[:unix_end].to_i
+      month_start = params[:month_start].to_i
+
+      if params[:unix_start].present? && params[:unix_end].present? &&
+         unix_start.between?(0, max_unix_time) && unix_end.between?(0, max_unix_time)
+        agenda_start = Time.at(unix_start).utc.to_s
+        agenda_end = Time.at(unix_end).utc.to_s
         events = EventNews.agenda_events(agenda_start,agenda_end,read_more_url_root)
       end
-      render json: {"events" => events,"calendar_title"=>get_calendar_title(Time.at(params[:month_start].to_i).utc)}.to_json({"frontend" => true})
+
+      calendar_time = month_start.between?(0, max_unix_time) ? Time.at(month_start).utc : Time.now.utc
+      render json: {"events" => events,"calendar_title"=>get_calendar_title(calendar_time)}.to_json({"frontend" => true})
     end
   end
 
@@ -1030,4 +1039,4 @@ class EventNewsModsController < ApplicationController
     month_name = I18n.locale.to_s=='zh_tw' ? now_date.month : I18n.t("event_news.month_name.#{now_date.month}")
     I18n.t("event_news.calendar_title",year: now_date.year,month: month_name)
   end
-end
+end
\ No newline at end of file