How can i know when raid bosses will spawn?

[OlympicVavik]

Hy I am now doing the verdandi terminal quests and i saw that there are a lot of raid bosses fights like omegamon, dex duro colossal etc. and i wanted to know how can i know when a raid boss is spawning?. i am asking it because i know one player who knows the exact times for the raid bosses.

[adri]

they have time atfer dead 8 hours for dex , 5 hours for omega 3 hours atfer debuff x program start , royal knight 2 hours , dinotiger 10 minutes