(Irish) Anocht = tonight (Spanish) Anoche= last night
Interesting...but apparently a coincidence, really. Or else all the way back to proto-indo-european
It's actually a cognate to just plain ole noche.
I also can't help notice a similarity to the German "Nacht", which means "Night".
What makes you think it's a coincidence?
Tá blas dorcha ag anocht.