Change monster spawn by using .txt

[Zero Human 0]

Hey, everybody,
is there any way to use 2 different mobspawn.txt for the same map?
For example,  0 am to 12 am Porings spawn on the map and 12am to 12pm disappear the Porings and Familiars spawns.
The script calls prontera_day.txt and prontera_night.txt.

At the moment I run monsters on the specific maps with an onEvent that spawns and changes at the desired time.
But it would be much easier if could run it over the .txt. (npc/re/mobs/fields/prontera)

Hope you understand what I meant. 😕

[Kuya Jeo 120]

OnClock0000:
	killmonster "yourmap","all";
	yourmap,0,0,0,0    monster    Poring 1002,300,0,0
end;



OnClock1200:
	killmonster "yourmap","all";
	yourmap,0,0,0,0    monster    Poporing 1031,300,0,0
end;

try this one

[Zero Human 0]

At the moment I have it running via a script.
This is not about an event where monsters are to be killed once. It is about a real spawn.
So the monsters have to spawn again after the kill.
Like I said, it all works so far, 
but i don't want to run every map through a script. it should go over the normal monster spawn .txt,
which are listed under "npc/re/mobs/fields/".