Nowadays, there are several demand response (DR) programs which are offered to electricity customers in different countries. Accordingly system operators are usually facing with appropriate designing and pricing of DR programs that could be incentive for consumers to participate in such programs which lead to improvement of some technical and economic characteristics. In this paper, time-of-use (TOU) program as a prevalent program is modeled linearly based on self and cross elasticities. In order to determine TOU program tariffs, a joint optimization of operation cost and customers' benefit is proposed based on security-constrained unit commitment (SCUC). Also some supplementary constraints are considered such as daily energy consumption requirement and demand response potential limitation. The proposed model has been formulated by GAMS programming language and solved using CPLEX solver. The validity of the proposed method is tested over the IEEE 24-bus test system. In this regard the impact of calculated TOU rates on financial profit of all customers, improvement of peak load and operational cost are shown.