>"metric-style" time

So is that 1 day = 10 hours = 100 minutes = 100 seconds or some other combination?

Ah - I've now found a good website explaining it all:
http://zapatopi.net/metrictime.html

So it could be the method mentioned above or it could be in pure decimal fractions of a day - deciday, centiday, milliday, microday (they need a name for the next one down - any suggestions?, this is a word list, not a maths list after all)

To translate my original time: 03:15:40

With method 1:
03 would become - 1.25, 15 would become 25, and 40 would become 66.6666667 (ish) giving us 1.25:15:66.6666667
I can see it catching on - especially with talking clocks.

With method 2:
3 hours = 0.125 day
15 minutes = 0.0104167 more or less
40 seconds = 0.0004629 give or take a bit
Giving us 0.0004629approx in Chicago at the time I made my post in Edinburgh - I'll remember that time forever!