The selection of trip timing and mode are two critical decisions of each commuters’ daily travelling behavior. Since there are significant differences in observed home-work departure time distributions by different mode of commute, this paper provides an integrated treatment of commute mode and time of day explicitly considering the influence of mode selection on departure time selection. In this paper the joint model of mode selection and homework trip timing is estimated using a discrete-continuous econometric model, which allows for unrestricted correlation between the unobserved factors influencing the two decisions. Strong correlations between unobserved factors influencing mode selection and trip timing are found. Furthermore the estimated model proves that age, gender, household member structure, activity and travel characteristics of the commuter are all important influencing factors for the two decisions. These findings have important implications for commuter travel behavior analysis and transportation managemnet.