temh₁-es-
“period of heat/dark, time segment”tempo, temporal, temporary, tense
Abstract from *temh₁- giving Latin tempus, English tempo, temporal, temporary, tense, contemporary.
Discussion
The PIE form *temh₁-es- (period of time, a cut or measured segment) derives from the verbal root *temh₁- (to cut), with the s-stem suffix *-es- producing a noun of result. The literal meaning is "a cutting" — time conceived as something divided into portions, measured out in segments. This is the root that gave Western civilisation its word for time, and the metaphor it encodes — time as something cut — has shaped how European languages think about duration, speed, and rhythm.
Latin tempus (time, season, the right moment) continues the root directly and is one of the most productive Latin nouns in English: temporal (pertaining to time), temporary (lasting for a cut portion of time), contemporary (of the same time-cut), extemporaneous (out of the time, improvised), and tempo (the speed of musical time, borrowed from Italian). The word tense (grammatical tense — past, present, future) descends from Latin tempus through Old French tens, making every sentence in every European language a deployment of the PIE cutting metaphor.
The connection between cutting and time is not arbitrary. Early societies measured time by cutting: notches on a tally stick, divisions on a sundial, the cutting of a day into hours. The Latin phrase tempus fugit ("time flies") and the English expression "to cut it short" preserve the ancient equation of temporal management with physical division.
Greek témnein (τέμνειν, "to cut") preserves the verbal root in its literal sense and gave English: anatomy (aná + tomos, "cutting up"), atom (átomos, "uncut, indivisible"), tome (a volume, literally a cutting — a section of a larger work), epitome (a cutting upon the surface, an abridgement), and the surgical suffix -tomy (appendectomy, tracheotomy — cuttings into the body).
The semantic divergence between Latin (time) and Greek (cutting) preserves two branches of the same PIE concept: Greek kept the physical cutting, Latin kept the abstract result of cutting (the measured segment). Together they reveal the original metaphor in full.