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Due to inactive updates from previous source, thus, if you found any mistake or update, update me here via commenting below.
Party Quest Boss (Part 1)
Party Quest Boss (Part 2)
Party Quest Boss (Part 3)
Summoning Boss: King Goblins (Korean Folk Town)
Summoning Boss: Captain Latanica (Boat Quay Town - Ghost Ship)
Summoning Boss: Krexel (CBD - Ulu City)
Summoning Boss: Targa & Scarlion Boss (Kampung Village - Fantasy Theme Park)
Summoning Boss: Papulatus Clock (Ludibrium Clocktower)
Summoning Boss: Zakum (El Nath Dead Mine: Zakum's Altar)
Summoning Boss: Bodyguards & The Boss (Showa Town: Hideout)
Summoning Boss: Horned Tail (Leafre Dungeon: Cave of Life)
Summoning Boss: Pink Bean (Timeless Temple)
Summoning Boss: Time temple sub bosses
Adventurers: 3rd & 4th Job Advancement Boss
Knight of Cygnus: Quest & Job Advancement Boss
Non-Event Boss (Level 60 & below)
Non-Event Boss (Level 61-100)
Non-Event Boss (Level 101 & above)
Boss (> Level 140) & Rare spawn normal monsters
Anti-bot Boss
*mn = midnight
Krexel = 24hr 
Papulatus = 12mn (Papulatus is twice per 24 hrs, resets at 12 midnight, in terms of entering the Papu map. The cracked piece of dimension you get from the npc also resets at 12 midnight. )
- Zakum = 12mn
Horntail = 12mn
Pink Bean = 24hr
Vergamont = 24hr
Auf Haven = 24hr
Capt Latanica = 24hr - BGs & Big boss = 24hr
Acknowledgement of Source
http://forums.asiasoftsea.net/showthread.php?t=617146 
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