This paper presents an algorithm for wireless sensor networks which combines time synchronization and efficient data gathering with minimal overhead and no special message for synchronization. The synchronization part is novel, using multiple ways between the reference and the node to be synchronized to. The data gathering part extends a previous work [1]. It uses various connected dominating sets for increasing the lifetime. This algorithm is calibrated to Micaz® motes by performing some experiments with them. The synchronization part is then validated on a simple Micaz® network.