Dracopoulas v. Rachal
In Dracopoulas v. Rachal, 411 S.W.2d 719, 721 (Tex. 1967), the Texas Supreme Court held unenforceable an oral modification that extended the time for performance indefinitely. See Dracopoulas, 411 S.W.2d at 722.
The court reasoned that the termination date of the contract was the "hinge upon which still other contractual rights and duties turn," and extending the termination date indefinitely would destroy other contractual provisions that depended on the termination date to become operative. See id.