This year’s Texas sales tax holiday begins at 12:01 am, Aug. 10, and goes through midnight on Aug. 12. Most clothing, footwear, school supplies and backpacks costing less than $100 are exempt from sales tax. Shoppers will save about $8 on every $100 they spend during the weekend. The tax holiday is also a big boon for merchants, many of whom see a 10 – 15 % increase in sales.