There are a number of reasons why the sprinklers may not come on from the automatic program. Assuming the controller will run the zones from the controller manually, you most likely have a programming issue.  Below are a few possible causes to the watering cycle not starting:

Check the Programming:

• Is there a watering Start Time programmed into the controller?   
• Is the Watering Start Time programmed with correct time of day (i.e. AM or PM)?
• Is the Current Time set correctly (i.e. AM or PM)?
• Is today a Water Day? (i.e. Controller may be set for Even Days and today is the 21st)
• Is the controller set on Interval watering days?
• Are there Station Run Times programmed into the controller?

Is there a rain sensor wired into the controller?

• Look at the “Sensor” terminals on the controller. If there are wires connected to the “Sensor” terminal screws, there is a sensor on the irrigation system.
  By sliding the Rain Sensor switch to the “Bypass” position you can over-ride the active sensor.
• Look at the controller display, if the “Sensor OFF” message is displayed, the sensor is activated and inhibiting the watering cycles.
  By sliding the Rain Sensor switch to the “Bypass” position you can over-ride the active sensor.

If everything here appears to be normal, please use the following article for the next step in troubleshooting: No Zones Running.