The TOPGREENER TGT01-HN digital astronomic timer switch is an in-wall programmable light switch with automatic dusk and dawn adjustments. This light switch timer combines the features of a 7-day programmable switch with astronomic settings to allow users to fully automate their lights, fans, and more! The astronomic feature automatically adjusts dusk and dawn times based on geographic location and the time of year, allowing users to automate their lights based on the sunset and sunrise. Simply select your time and zone and the TGT01 will do the rest! The timer switch also includes an auto daylight savings time feature to ensure that scheduled programs automatically adjust for time changes throughout the year. In addition to 7-day programmable settings, this astronomic timer switch includes a “random mode” for added security when you are away from home. Random mode varies the programmed schedules by a few minutes to make the home appear occupied and deter potential intruders. Programmed schedules can always be overridden with the switch’s manual ON/OFF button. This allows users to keep the load ON/OFF indefinitely or set a one-time countdown timer. The digital timer switch features a bright, backlit LCD screen for easy programming and an internal memory that backs up saved settings in the event of a power outage. This switch is compatible in either single-pole or 3-way applications and a neutral wire is required for installation. The astronomic digital in-wall timer is perfect for any area of the home that could benefit from timed lighting or fan control, such as a dining room ceiling fan, patio lighting, child’s bedroom, or living room lighting for the whole family. This timer switch features an white color and it ensures that lights and fans are only on when needed, conserving energy and lowering electricity bills as a result. With this convenient wall switch you truly can just set it and forget it. This product is UL listed and includes 3-year warranty.