Because of anomalies such as the fact Illinois ignores DST, the clocks are not always 100% automatic. You have to tell them the timezone, and sometimes you must tell them the approximate time. Here is a typical fudge to deal with the fact Illinois ignores DST.

The clocks work all through the USA and southern Canada, though you need good radio reception.

Manufacturers call them analog atomic clocks and digital atomic clocks, though there is nothing radioactive in them. They are merely radio-synchronised from a government atomic clock.

When I was a child a read a story about a man who devised a scheme to keep all the world’s clocks in sync. People thought him mad. Today you have to be mad to put up with an inaccurate clock or one that keeps forgetting its time every time it loses AC power or its batteries run down.

These clocks are now barely more expensive than ordinary ones. Here are some web stores that have extensive stock:

•   WeatherBuffs.com atomic analog, digital, mantel clocks and watches
• Weather Connection atomic analog wall clocks atomic digital wall clocks atomic alarm clocks atomic watches
• The Clock Depot
• Radioworld Canada. Mostly small travel clocks.
• BRG Canada. Commercial clocks. Ethernet synched clocks. Building-synched clocks.

Atomic Radio-Synched Clocks
Model	Cost mindprod.com CurrCon international currency Applet needs Java installed for it to display prices in any world currency. mindprod.com CurrCon international currency Applet needs Java installed for it to display prices in any world currency.	Appearance	Notes
Oregon Scientific Atomic Digital Desk Clock	$29.00 CAD		MRM-983A. Keeps accurate time by monitoring a radio signal from a US government atomic clock in Colorado. It also displays room temperature in Fahrenheit only. 12 or 24 hour digital display. 8.763 × 11.43 cm (3.450 × 4½ in). I have one on my desk. I watched it automatically leap an hour forward on the spring DST change. It made the change about 2:02 AM. It is very simple to use since other that setting the time and date to get it started, it stays in synch automatically.
Honeywell Atomic Digital Wall Clock	$40.00 USD		Model RCW33W. Keeps accurate time by monitoring a radio signal from a US government atomic clock in Colorado. It also displays temperature inside and out using an included remote sensor. 12 or 24 hour digital display. 11.25" x 6.75"
Lacrosse Atomic Analog Wood Wall Clock	$23.00 USD		Model WT-3122J. Wood. Keeps accurate time by monitoring a radio signal from a US government atomic clock in Colorado. 12 hour analogy display. No temperature display. 12" diameter.
Lacrosse Atomic Digital Wall Clock	$18.00 USD		Model WS-8007O. Keeps accurate time by monitoring a radio signal from a US government atomic clock in Colorado. It also displays temperature inside and out using an included remote sensor. 12 or 24 hour digital display. 29.21 × 19.05 cm (11½ × 7½ in)
Lacrosse Atomic Plastic Analog Wall Clock	$18.00 USD		Model WT-3101H2. Plastic. Keeps accurate time by monitoring a radio signal from a US government atomic clock in Colorado. 12 hour analogy display. No temperature display. 10" diameter.