I'll just make this table here.
Generally, each event that involves a mob drop has 17 possible spawn points. However, I'll only reveal 1 of them. You're on your own for the rest of the 16 spots. They generally are in the maps no higher leveled than Tarkan.
| Event Name | Event Time | Event Awards | Location | 
| Red Dragon Attack Gold Dragon Attack
 Dark Wizard Attack
 Golden Mobs Attack
 | Once in 2 hours on 00 | BOKs | Various 
 | 
| Blue Event (Moon Rabbit Attack)
 | Once in 3 hours on 40 | Jewels of Soul Jewels of Bless
 Soul of Eternal
 Gemstone
 Cursed Gift*
 | Devias4 | 
| Summer Event (Karagasa Attack)
 | Once in 2~3 hours on 30 | Various Gears PCPoints
 | North Lorencia
 | 
| Rain Item Event | Once in 3 hours on 10/40 | Various Jewels | Lorencia Ring
 | 
| Happy Hour | Once in 3 Hours on 05 | Exp rate 7650x +Item drop rate
 | N/A | 
| Hit And Up | Semi-Randomly on 20 | Points gain+1 when lvl up | N/A | 
| Boss Attack | Semi-Randomly on 50 | Boss Drops | LorenValley | 
| Green Event | Once in 3 hours on 50 | Green Named Items Rate UP
 | N/A | 
| Blood Castle Chaos Castle
 Illusion Temple
 Doppelganger
 | Refer In-game | Various Rewards | N/A 
 
 | 
*You may not want to open auto pickup for jewels, or you'll be in very nasty surprise.
There are also GM events, held by GM, that happens randomly with random prices.
We are still coming up with more in-game events, keep focused!