There are three reasons why your sprinklers may not be watering:
The most common reason your sprinklers are not watering is because the rain sensor is active. Do you have a rain sensor on your sprinkler system? If so, slide your sensor bypass switch into the "BYPASS" position (on an SRC, turn the dial into the RUN (Bypass Sensor position). On properly wired systems, this will over-ride the rain sensor and allow normal controller operation.
Check your programming in the controller, specifically Watering Start Times and Water Days.
Is the water on? During "Spring Start Up", you must open the irrigation water supply valve. When the irrigation system is "Winterized," the water supply is shut off.