To the best of my knowledge (and maths!) it's Thursday, 13 March to Monday 17 March, 2014.
You can calculate future dates by looking up the date for Shrove Tuesday. The weekend following is the Santa Cruz Carnaval. The weekend after this is Los Gigantes Carnaval, starting on the previous Thursday. Subject to agreement of the Carnaval Committee. The date for Shrove Tuesday is all to do with equinox's and full moons, so varies dramatically each year.