sprinkler timer cycling

I replaced a sprinkler timer recently (Orbitz) and now my sprinklers keep cycling through and won't shut off until I maually shut them off. Any ideas as to the problem? Thanks in advance

Either it is defective or is programmed improperly. NOTHING we can do to diagnose it without being there.

Try doing this there might be overlapping start times programmed. Clear all start times and then enter only one start time. If you would like to water more than once a day, enter the next start time for later in the day. A start time is the initial time of day when the timer will begin to water. Each station or zone will then water in sequence according to its chosen duration. Multiple start times allow you to water all stations more than once in the same watering day.