[plt-scheme] GMT date stamps and time-zone-offset

> The subject of time has to put it mildly been convoluted. To me the
> most curious time related concept is leap seconds.
>
>

UTC runs at a rate determined by atomic clocks.
The earth rotates at a slightly erratic rate determined by many things.
Leap seconds are occasionally needed to make up the difference.

Some argue that the effort isn't worth the trouble:

http://www.cl.cam.ac.uk/~mgk25/time/leap/

rac