Is pretty useful if you want hunting slime (in swamp)
So Like
Moon Phase : 0 - 7
0 Full moon
1 Waning gibbous
2 Third quarter
3 Waning crescent
4 New moon
5 Waxing crescent
6 First quarter
7 Waxing gibbous
https://minecraft.gamepedia.com/Moon#Phases

Request to add weather and moon phase information . thanks

Support! Was coming here to make this exact suggestion. Useful for any mechanic that involves moon phases, vanilla or otherwise.

Yeah. Especially for hunting your first slimes. :-)