The ancient Grecian sages, Pittacus and Thales, both of whom lived in the sixth century B.C., and the Latin writer of fables, Phaedrus, who lived in the first century A.D., all advised the ambitious person to seize the opportunity or the occasion at the moment it was presented, so this saying has been attributed to each of them.
It was Phaedrus, however, who described “Opportunity” as having a heavy forelock but being completely bald at the back, thus implying that one could not wait until opportunity had passed before hoping to take advantage of its offers.
In agreement with Phaedrus, English usage of the expression during the sixteenth century was, “to take opportunity by the forelock.”
The switch from “opportunity” to “time” came about through the personification by artists of “time” as an old man carrying an hourglass and a scythe, and, borrowing from Phaedrus’ description, bald behind, but having a forelock.