Free Chicken Fajita Taco at Taco CabanaIn celebration of National Taco Day, Taco Cabana will offer all of its customers a free Chicken Fajita Taco on Tuesday, Oct. 4, from 5 to 8 p.m. No coupon is necessary to get this freebie. The giveaway also coincides with Taco Cabana’s Happy Hour (from 4-7 p.m.), so you can also enjoy drink and appetizer specials while you’re there, if you so choose.