Hi,
Great news !
I guess that for most countries, WLM is as usual from 1st to 30th Sept (I can confirm it's true for France).
Ireland has no page yet : https://commons.wikimedia.org/wiki/Commons:Wiki_Loves_Monuments_2015_in_Irel... :( but there is indeed pages on https://commons.wikimedia.org/wiki/Category:Images_from_Wiki_Loves_Monuments... weird...
Cdlt, ~nicolas