|Metric SI, System International, still had old-English time, despite establishing the scheme and schema for Metricization|
Standard Metric time divides the day into 40 demurs or 40,000 centigrad hesits (40 kilohesits).
The old-English system of measure with its expediency of units, inches, feet, yards, rods, furlongs, miles (land, nautical), fathoms, knots, hours, degrees, minutes, seconds (angular, time), gills, gallons, pints, barrels, pecks, bushels, ounces (troy, avdp.), pounds, tons,..., and irregular factors, 2, 3, 4, 5, 5.5, 6, 12, 16, 24, 40, 60, 220, 2000, 2025 (34 52), 6076 (22 72 31),..., used mostly in America..., was parried centuries ago by the French Métrique Système International which proffered regularized stabilized conceptualized decimalized, meters, liters, grams, moles, candelas, Kelvins, and Amperes (they'd discovered electricity by then), plus compounded-derived units (but 'watch for falling units' virtual-unitized aka 'dimensionless' angles π-radians-per-circle and 4π-steradians-per-sphere), and units of convenience subsized and supersized, and subsequently extended to grads and oodles more (grads are metric, oodles are not)--with prefixes for factors by convenient powers of 10, deca, deci, hecta, centi, kilo, milli, mega, micro, giga, nano, tera, pico, peta, femto,..., * and weights done by their water-mass-equivalent grams and tonnes (prototyped in expensive metal alloy found inaccurate and 89 years later conceptually slighted in deference to the prototype); and force, energy, momentum,..., done in terms of the other units; replacing temperature degrees Fahrenheit and absolute Rankine, by Centigrade-now-Celsius and Kelvin (used most originally in electrophysics)...
* (poorly matched nomenclature for those elsewise in-language e.g. k 'kilo' G 'grand' thousand but G 'giga' billion-Amer. not-Brit. and K 'grand-binary' 210 = 1024.)
Even money left old-English shillings and pence, for decimalized francs and centimes, dollars and cents, and recently, euros and cents.
But time, that half-dimension that remained when DANIEL counted steps two-dimensionally on the horizontal plane and weighed the vertical climb, then divided forward-only time past from future, and distance by time, in rates of travel and travail,--count, count, weigh, divide, he explained the writing on the wall [REF: MENE MENE TEKEL UPHARSIN],--metric SI time was stuck in the gear of old-English hours and seconds: rate-of-travel was trifurcated in km/h or in c-g-s or m-k-s: kilometer-per-hour for road traffic, centimeter-gram-second for physical-chemistry sciences and laboratory measurement, meter-kilogram-second for larger applications and astrophysically small observation...
The drawback for acceptance was that new-metric SI changed public roadsigns to keep private clocks old-English.
Nevertheless, Metric SI did provide the means and measure for establishing a true, metric unit of time,--but not its nomenclature set: Its original definition of linear measure was based on a moonoid-bludgeoned macro-scale Earth parameter, the mean polar circumference, firstly quadranted in circularity, from the equator to the north pole, before graduating linearly in decimal powers, factors of 10, the meter a ten-millionth, kilometers, millimeters, etc; and laterwise the grad a hundredth, centigrads, etc. This basic Earth-circle-quadrant-decimal pattern has been reexamined and reproposed in centuries since but in the pursuit of comity was always to 4-or-6-digit similarity with English time, which resulted in minute-thirds and second-fifths neither particularly convenient nor familiar... Alternatively dividing a day decimally, as gained faveur with the revolutionary French Republican Calendricists on 360 days per year, contradicted the basic Metric systematiques; and neither was adopted by the Committee which acted to retinue the old-English second for subsequent rationality. But nor was old-English the basic metric; it was merely de facto.
Changing it subsequently, has been perennial discussion among government timekeepers, but consideration of a five-digit 'hand' which makes a convenient and recognizable two-second unit (perhap like the kilogram is a two-pound unit) was not deemed superefficient, to take it up: Metric SI as-was had already exacted its troll--and there did not appear much to recover, as hours and seconds could be counted decimally, too: where time was measure passing, not part of a day. However, the five-digit metric possibility harbors a secret that, had it been known, probably scared the Committee out of its dither: for it causes the most challenging of all in situ publications, the ubiquitous road speed sign, to not-change, n'even by half a usual increment of 5 mph, over the usual 0-70 speed range--and had the Committee selected this solution it would have squared-off with Traffic Court and probably figured it'd never win against their motoric tomes, judges being lenient but not wacky...
|The centigrad existing; the nomenclature, hesit, demur, is new, 1996.|
THE HESIT, UNIT OF METRIC TIME, NOMENCLATURE
The Standard Metric time unit, the hesit (cf hesitation), is one centigrad of heliocentric year-average Earth equatorial rotation, a ten-thousandth of a quarter mean solar day (retaining the 'thumb' of circle-quadrant and four 'digits' of powers-of-ten: the 'right hand' of time, most-usually written in the thumb-index-three-finger 'ow' 39.999-format). This can be put to atomic clock accuracy for the epoch. 
THE KILOHESIT DEMUR, DECIMAL SCALE, NOMENCLATURE
40 kilohesits is a day: a hesit h = 2.16 seconds. A kilohesit or demur (cf demur: delay, linger) is 36 minutes, slightly more than a half hour--convenient for television schedules and schools taking 2 or 3 per typical period. The metric demur nomenclature derives from, demi + heure/hour/uhr (French half+hour/+English/+German o'clock; also Biblical millennial time began ca Ur 'ancient' eastward in Eden). A hectahesit hh = 3.6 min. is convenient scale for intervals and interludes...
The half-day metric clock spans 20 demurs, 10 demurs morning AM and 10 demurs afternoon PM (ante/post meridiem), and repeats for evening PS and pre-morning AS (post/ante semidiem-solariem)... a half-day clock cycles in 20 demurs with a day/night-indicator, a quarter-day clock in 10 demurs with a quadrant-indicator.
Posted mph rates of travel are 3.56% faster by meters-per-hesit than by old-English miles-per-hour; Metric 70 mph is old-English 72.49 mph, not half-way to the next 5-mph graduation at most speeds on American freeways, like 1.0 cm difference in tire radius; relegating changes of roadsigns to implement SI metric, as bilingual. Non-metric speedometers are 3.44% slower than metric.
Recognition of the Standard Metric system as in situ, provided the invention of renomenclaturing, does not yet constitute retroaction: the ratio-constants need be enumerated; For examples, The speed of light is 647,551,709.28 mph metric ; Acceleration due to gravity at the Earth sea level is 45.7 mphph (m/h²) metric...
The Standard Metric system taxonomy enumerates in the units canon of meters-grams-hesits, m-g-h. Alternative canons, m-k-h, m-k-k, m-k-d, m-t-h, c-g-h, [kilograms, kilohesits, demurs, tonnes, centimeters], are decimal power scale equivalents... kmph [kilo-mph] refers to supersonic/hypersonic (e.g. HSST shuttle transport) and spaceflight regimes upto solar wind velocity...
Other metrics may change in time: Temperature, for example, Calibrating by water (H2O) at a speed, estimates temperature as its kinetic energy equivalent similar to Fahrenheit (Ger. speediness): At 50 mph metric as one degree metric (1.0449°F) its meltingpoint would be 470.4° absolute (491.67°F = 459.67+32), and boilingpoint 172.3° hotter (212°F), and 1 eV ≈ 19,990°metric-Fahrenheit (11604.5°K; and which suggests a more 'native' definition for 20,000°metric, or, consider v = 10-7c, H20 ≈ 18.015 amu × 931.5 MeV / amu × ½ × (v = 10-7c)2 × 11604.5°K / eV ≈ 0.9737°K closer to 1°K, 1°C).
Metric time also brushes reproducible music pitch commonality, ever critiqued: Tones are metricized by twelfth roots of binary factors upon an initial multiple per second; A-440 cps being the contemporary standard, in hesits A#-1000 cph registers 0.7% low (1.5% high by the C-256 cps classic) though the definition of A# was equally debated since before this tempered scale was assumed. Notable alternatives include pitch register memed on historic year numbers: F-1492 cph for Columbus landing in America, Gb-1582 cph for the Gregorian Calendar, high-Ab-1776 cph for American Independence, high-A-1901 cph (octave-eqv. A-440 cps) for the American Standard Version Bible (high-A-1885 for the English Revised), high-A#-1996/2000/2001 cph for the new millennium (true/assumed/numeric).
Metric time does not affect the calendar, as its basic unit is the day with subdivisions by demur (40th) and hesit (sub-thousandth); however, the old Roman February can be adjusted to the common mode and mean length by reassigning January 31st as February 0th (observing the advent of Computer Sciences *) and March 1st as February 29th/30th (per leap year), giving February 30/31 days, and January and March, 30; (And similarly May 1st as April 31st, and July 1st as June 31st, more nearly regularizing the whole year).
|Accuracy goes with year-day integrations, and tidality.|
 To atomic clock accuracy, h = 19,856,084,620 cycles of Cesium-clock before counting leap-hesit; or, h = 19,856,085,130 cycles, = 2.160000055 seconds, accounting 0.37 leap-hesit/year epoch AD 2000.
 To atomic clock accuracy, c = 647,551,709.28 mph, or, c = 647,551,725.769 mph, accounting 0.37 leap-hesit/year epoch AD 2000.