Is there a law in Texas for being required to work 8 to 12 hours per day 7 days per week with no time off?

There is no black and white limit to the number of hours an employer can make an employee work each day.  However, when the number of hours worked by the employee in a single week exceeds 40, the employer must pay the employee 1.5 times his or her normal hourly rate for each hour in excess of 40.  By way of example, if the employer required an employee to work four ten-hour days in a row in a single week, then let the employee off the remainder of the week, no overtime would be due.  If that same employer worked that employee addtional days in the same week, he would have to pay him or her overtime for all hours on those additional days.  An private employer cannot avoid the overtime requirement by making an employee work more than 40 hours in a week and then giving him or her time off the next week (the rule is different for a government employer).