You should reset the time of day on your timer twice a year when the time changes. If you have an incandecent system you will have to change the light bulbs when they burn out. A lot of people prefer to change their bulbs once a year. If you have an LED system there are no bulbs to change.
Ron offers an annual maintenance program which will extend the life of your system. This includes changing light bulbs, cleaning lenses, applying a noncorrosive compound where neeeded and repositioning fixtures if necessary. This service is availble even if he did not install the system.