I've just published a fix to the reference implementation of
SRFI 19 made by Will Fitzgerland, its author.  Thanks very
much to Geoff Taylor for reporting the bug.

Here's Geoff's bug report: "You know there's a bug in the
(copy-time) implementation in the reference implementation,
yes?  The nanoseconds and seconds parameters are the wrong
way round."

— SRFI Editor