It's in degrees, minutes and seconds. 360 degrees in a day, 60 minutes in a degree, 60 seconds in a minute (same as math). An Earth Time second is 1/15th of an SI second, which makes a NET minute 4 SI seconds. It's based off of latitude zero, which is GMT 0.
I guess this makes me a geek or something, but of the various alternate clocks, this one is the only one that makes sense.
The "metric" (aka decimal) calendars and clocks are impractical. One says a year is 100 days. This is idiotic. A year is one revolution around the sun. A day is one rotation on axis in relation to facing the sun (one absolute rotation is 23 hours and 56 minutes, but whatever, right?).
Any alternate time system must keep that in mind. If you can't handle counting in degrees (a year is (1 + (5.25/360)) days per degree) then really you have no business making a time, date or any other number system.
There's also a guy who made a hardware digital net clock. It doesn't cover NET seconds, but he's considering a PIC based clock and a watch, so I emailed him about it. :)
I used revjim's update checker tool to make an rss feed of Andrew Cleary's site where he has info on his NET clock.