As mentioned, I'm also a believer in 'reason.' So, everyone, in every world, speaks English so every reader can understand. Well, I get that except at that point I'd expect they'd apply English words properly (or make an attempt). Since it's more reasonable that they speak English as a second language, I'd then expect and welcome their own language used where there is confusion, or where there isn't a direct English word to express what they mean...like your time example.
But--and this is just my opinion hoping to help, imaging how it might be received--with 'centi, milli, and jiffy' all being graduations or expressions we use in English, but that neither apply as they do in English or are some alien language word, goes against the conditions I set (for myself) above.
As an example, a barbarian language I developed used the following words (in brief):
Ba: visible light, sight (Ba'sot = bright, Ba'mon = shaded or shadowed, Ba'fed = dark)
Ke: 2
Kef: a stride or pace (kef'sot = to walk, kef'mon = fast walk to jog, kef'fed = to run)
Kot: season, (Kot'sot = Spring, Kot'mon = Summer & Fall, Kot'fed = Winter)
Lum: second moon
Lus: sun
Sosh: life itself
Sosh'lums: Time in general, days of life
Ba’lums: Specific times during the day (ut’ba’lums’sot = sunrise, ut’ba’lums’mon = mid day, ut’ba’lums’fed = sunset, un’ba’lums’sot = dusk, un’ba’lums’mon = mid night, un’ba’lums’fed = dawn (dawn and dusk the half hour before the sun crests/passes the horizon))
Ba'mons: distance of movement of a shadow (word ba'mons would be spoken as a distance. Is shown or described by spacing of hands, or in number of strides to show an exact time or time passed = minutes and hours) E.g.: Ke'kef ba'mons, a shadow lengthening from noon (none) to two strides distance
Lums: passing of the second moon, a day (word lums spoken as a count of how many is shown on fingers = days)
Lumuns: the second moon completing 1 full phase cycle = months
Kot'feds: passing of winter seasons = years
Point being, the barbarians have their language they build upon. When they spoke 'crown' (English), pride found them often using their own words to replace English words. But, those barbarian words actually meant something and were used to build more intricate concepts.
So, come up with words as you need them that fit your race and have reason to that race. Make those words fit your race and have reason.
Explain it or make comparisons as needed or when opportunity presents itself, but otherwise don't. My example in the first post a way to do that of gazillions.
Just my opinion.
K2