I suspect that dps was implying that some thymes are annual in some
climates. We don't find lemon thyme as hardy here as common thyme for
instance, although it will overwinter just fine in a sheltered location most
years - but yes, in ideal climates, thymes are all of a perennial nature and
are only treated as annuals in hostile climates. On the other end of the
spectrum, I think that some are done in after a season in the heat and
humidity of the deep south.

"Pam - gardengal" Thyme comes in a mat-like perennial form commonly used
as a groundcover and
in shrubby forms ranging in height from a few inches to a few feet with
winter hardiness ranging from zone 4 upwards. But it is most definitely
evergreen and it is most definitely NOT an annual. Perhaps you were
thinking
of salvia?

pam - gardengal