A timed spell trigger

Can someone tell me how to make a trigger that uses a spell in a region? i already know how to make it go off at a certain time i just can't get it to go off where i want it to.

Your description of what you want is abysmally vague.

What i want to know is how to make a spell go off in a region, preferably the entire region. I already know how to make it go off at a certain time i just need to know how to make it go off in a specific region now.

You have a dummy unit cast it where you want. You can't just cast a spell, some unit has to cast it.

You need to specify what kind of action you want to take place "in the region". If it involves affecting units in a certain way, you must enumerate each unit in that area, for example.