WoW:API time

time

Returns the number of seconds since the unix epoch. Note that time() works from the local clock, so it is not synchronized among all clients. This is exactly like the C time(0) function. Very useful for seeding random numbers if you don't need millisecond precision, etc.

DEFAULT_CHAT_FRAME:AddMessage("Current Time: "..time())

Might produce:

Current Time: 1118722038

--Drena