Internet Protocol clocks use an existing Local Area Network (LAN) or Wireless LAN (WLAN) to receive time corrections. In this way, they'll synchronize time with one another and automatically update twice per year for DST.
An added benefit is that they'll be at the same time as any computers on your network.
These clocks are part of a synchronized time system controlled by a master clock that delivers time corrections either directly by wire or over radio waves.
Schedules can be programmed through a web interface for these time systems in which bells, lights, and other switches can be triggered on time with the clocks.
There are other clock options that will adjust for
AllSet® clocks have an internal calendar and hold or advance their hands at the right time of year.
Radio-controlled clocks will correct by receiving a signal from NIST in Colorado.