The weekend of the 24/25 March looks shiny and lovely from where I'm standing. The one after is currently also empty on the calendar but a word of warning: school holidays start on Friday March 30 and flight prices will no doubt shoot up accordingly.
Leoba is wise! Ryanair has flights from Stanstead to Shannon for £9.99 each way (plus taxes) on the Friday and Monday of the first weekend. The following weekend, prices go to £39.99 each way.
If thats the price difference on cheapo flights like Ryanair, you can imagine what other flights will be like.