/npc/instances/EndlessTower.txt
set .@dun_lim_time,etower_timer+604800; // 1 week
Replace with:
set .@dun_lim_time,etower_timer+172800; // 2 days
/db/quest_db.txt
60200,604800,0,0,0,0,0,0,"Endless Tower Effect"
Replace with:
60200,172800,0,0,0,0,0,0,"Endless Tower Effect"