A water timer is revealed. The water timer includes a base assembly, a valve assembly and a display module. The base assembly consists of a first housing and a second housing. The valve assembly having a conducting tube and a valve member is for turning on or off water supply. The display module is composed of a first space, a circuit board, an input member, and a rectangular column connected to t first space and used for receiving a battery box. The water timer features on that the display module is arranged with an integrated rectangular column used for receiving a battery box and the display module is locked on the first housing.
