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Agilent split itself into medical equipment and electronic test equipment. The former kept the Agilent name and the latter is now Keysight.

Unless you want to buy an HP 5071A Cesium Primary Frequency Standard. That got sold to Symmetricom, which in turn got sold to Microsemi.

There's likely at least one atomic clock at each physical facility and the time is synchronized at that facility using NTP. NTP has a resolution of 233 ps and network delays can be very well characterized over time. If you really care about proper time, as these folks likely would, you can have a separate physical network that does nothing but sync time and has no unpredictable traffic on it.

This stuff is all (relatively) cheap, too. My time server at home uses oven-controlled crystal oscillators disciplined to multiple time sources and it keeps time accurate to ~15 ns (even for the clients on my crazy wild uncontrolled wifi network, the jitter is measured in microseconds). And the whole setup only cost a couple of hundred bucks. Even atomic clocks aren't these big crazy lab instruments anymore (nor have they been for decades). You can buy nice little rackmount cesium clocks easily.

"You can't carry atomic clocks in your pocket, they're a tad too big for that."

Well, that *used* to be true!

http://www.symmetricom.com/products/frequency-references/chip-scale-atomic-clock-csac/SA.45s-CSAC/

Or, why not just go for an old fashioned atomic clock ?

http://www.symmetricom.com/products/frequency-references/chip-scale-atomic-clock-csac/SA.45s-CSAC/

GPS is used a a source for precision NTP servers such as these. Their industry solutions pages have a variety of situations where GPS is used behind the scenes.

RS-232 is still common in time and frequency devices.

When the power failed and they used the battery backup they all kept crap time, often being out by a minute per hour.

The error then would be about 1.5%. My guess is that your clock switches to an RC oscillator, and the frequency is then determined by tolerances of components. No crystal could be that bad.

Also another poster above mentioned that some clocks have an internal switch for 50 or 60 Hz.

One such switch costs more than a few crystals. Besides, it's another "maintenance" item that could be incorrectly set by the customer. I guess some clocks were made this way, after all, but I'm not guilty of that :-)

A simple crystal is cheap. A good calibrated crystal with temperature correction and such is not so cheap.

You most certainly don't need a TCXO. If you get one, like DS32KHZS#T&R, it gives you ±7.5ppm. This translates into 4 minutes of error per year if the frequency error is never adjusted or otherwise compensated for. There are temperature compensated crystals with better stability. However a common crystal comes with tolerance ±20ppm and hopefully has stability that is not worse. This figure translates into about 10 minutes per year, and that is perfectly fine for most people.

If, however, you can't accept the fact that you need to touch your clock at all, you have an option of using WWVB broadcasts at 60 kHz, or WWV that is broadcast on HF. Or you can get some Rubidium or Cesium standard.

The original press release is from January 18th 2011. Just sayin'. Of course this is a very nifty device and all that.

Taking out GPS won't disrupt the frequency across the grid. It just makes it much easier to keep synchronized. Highly accurate time clocks are kept already at each location and keep time just fine. GPS just helps keep them synchronized. Even prior to GPS we had land-based methods such as WWVB and WWV before that in North America. Again, the time clocks are already highly accurate and mostly need the initial signal just to set the frequency and time and to calculate drift. Here's one such vendor. They'll run just fine for months (years?) without losing frequency synchronization.

A long time ago (15 years!) I worked on the predecessor to http://www.symmetricom.com/products/gps-solutions/gps-time-frequency-receivers/XL-GPS/. I'm sure the modern day equivalent here doesn't cost 50k and will give you a local accurate time signal.