This is the custom moons addon to Enhanced Celestials 2 for my modpack here: link
Feel free to use this elsewhere, I don't really care what you do with it but here's the events that come into place currently:
Bright moon- extra EXP and vanilla mob spawning
Harvest moon- extra EXP and block drops
Bestial moon- more Lycanites Mobs spawning
Hero's moon- bit of extra EXP
Blood moon- more mob spawning
These go in a cycle; 1 for every 5 days. Controlled via datapack.

